Answer:
A.One should not think too much or too little of oneself.
Step-by-step explanation:
This could be seen in the action taken by Sir Andrew and his friend when being warned to lower their voices. Rather than acknowledged the fact that it is the proper thing to do, they imply mocked and make jest of malvolio.
This later led to him challenging Malvolio to a duel when he (Sir Andrew) thought that his honour has been bruised by the steward, Malvolio.