This is a complex question!
PKC helps mediate production of IL 6 and 10, so you have to infer if there is a mutation in the CARD11 protein resulting in an increase in the IL-6 and 10 it would likely be a result of PKC.
I would not worry too much about this question as it is very detailed in complex biochemistry, you will likely not see these concepts again on your MCAT. I know you are very keen and ask lots of questions which is great:) However, I promise you should not get bogged down on individual questions or details as being successful on the MCAT comes down to learning to eliminate answers based on things mentioned in the passage, it is very rarely based on prior knowledge.
Goodluck!