Kit Carson was instructed by Carleton to kill all Navajo men whenever and wherever he found them,

a. but Carson disobeyed him.

b. which Carson did in a flamboyant fashion.

c. so Carson ordered his men to carry out the orders.

d. which increased Carson admiration for Carleton

I think the answer would be : b. which carson did in a flamboyant fashion

Kit Carson was instructed by Carleton to kill al navajo men whenever and wherever he found them, but back then he was in ill and tired condition.

So in order to speed up the process, he started to burned navajo's house and field.