The context refers to a situation where the speaker is denying being the cause of lot of noise in the building due to being out at a party himself. The negative "couldn't have been me" is sued to indicate an impossibility in the past. Thus, option C is correct.
"Might have been" in option A is incorrect as it indicates the possibility that the speaker could have been making noise. But the second part of sentence B counters this and hence option A doesn't fit the context.
"Mustn't have been me" indicates probability. However, there is no chance of the speaker being home as he was out negates the probability.
"It shouldn't have been me" is incorrect as it does not concur with the context.
Thus, option C is incorrect.