Answer:
a) A military officer with a high rank or position.
Explanation:
Lieutenant is one of the several positions of leadership, that compose the military career. It is the officer who performs the functions of section chief or fraction commander, and replaces the captain in command of the subunit. In this sense, "lieutenant" is a military officer with a high rank or position.
I read the passage you wrote I think
The author's tone in a piece of writing is the author's attitude toward the topic.
The problem that he wrote was the division problem in which 36 is dificed into 4 groups of 9. Probably, he didn't mention the actual answer once 36 becomes groups of what 9 people if the students divided it, or how many are the 4 groups of 9 people all-in-all.