Was Cristiano Ronaldo injured for the Manchester derby or was he dropped?
The Portuguese's absence from the match dominated the build-up to the game after he was missing from the travelling squad the night before.
Ralf Rangnick said he had a hip flexor injury but Roy Keane in the Sky Sports studio was not convinced, saying "it doesn't add up to me" given how much Ronaldo is usually willing to go through to play in the biggest games.
Whatever the answer, it made no difference as Manchester City steamrolled Manchester United at the Etihad.
The scoreboard read 4-1 by the end of a punishing 90 minutes, United's pain deepened by Riyad Mahrez's initially disallowed goal being awarded by VAR.
The home fans were delighted by the decision amd revelled in the enormous gap between the blue half of Manchester and the red half, who used to rule their city and torment them so. How times have changed in Manchester.
Mahrez's second goal meant the scoreline finally reflected City's dominance and United's inferiority but, just as in the 2-0 defeat at Old Trafford in November, it wasn't about the scoreline.
Ronaldo did play in that game buthe had only one shot in a match that was aptly described as a 2-0 thrashing.
This was another demolition, slow death by a thousand passes.
United may have begun the game controlling possession but by the end of it they barely touched the ball, much less do anything with it.
In the second half City had 14 attempts on goal, United had none.
Would Ronaldo have made a difference? Probably not.
Many have suggested that for all his goalscoring prowess and winning mentality, Ronaldo has been holding United back this season. At 37 years of age, even with his remarkable commitment to staying in shape, he does not have the physique to keep up with the intensity at which the top sides in the Premier League play.
If Ole Gunnar Solskjaer was willing to indulge Ronaldo due to his talismanic abilities, Ralf Rangnick is not. He has been unafraid to leave the striker out of his starting line-up, such as last month against Burnley, or to take him off early, as he did in the win over Brentford.
But whether Ronaldo plays or does not, United still look like a team short on ideas and short on quality, despite having the biggest wage bill in the country.
And even though they headed to the Etihad having won their last three matches on enemy territory, there was a huge sense of inevitability about what took place.
Five defenders in the box could not prevent Kevin De Bruyne meeting Bernardo Silva's low cross and giving City the lead in the fifth minute.
United did show what they are sometimes capable of with their superb equaliser, sweeping down the pitch on the counter and Jadon Sancho delivering a top class finish to equalise.
It should have been a rallying cry but it was merely the exception that proved the rule City now have over them.
City players were queuing up to score before De Bruyne slotted his second, Harry Maguire failing to put the loose ball out and Fred standing static.
No players managed to pick up Mahrez for the third goal, the Algerian making the most of having so much space to pick his spot and hit De Bruyne's corner on the bounce to find the bottom corner.
Now the contest was over, City fans taunting the away end with chants, their players tormenting them with their passing.
The home fans were baying for more blood and Mahrez delivered. The offside flag looked to have spared United one more dose of pain but merely prolonged it, VAR delivering the final blow.
