Brown does not carry out the order delivered by henry because
a. brown is told by the captain to ignore the order.
b. brown is angry with twain.
c. brown knows it will lead to disaster.
d. brown does not hear the order.

Brown does  not hear the order.
a can't be the answer because captain never told him any thing
b can't be the answer as brown is friends with twain
c can't be the answer because brown certainly knows what's good going to happen instead of disaster.
so d is the answer

It is called a neutralization reaction