The history of Captain Nemo in the book "Twenty Thousand Leagues Under the Sea" remains a mystery. However, in the course of the narrative, the reader is given some clues of what forged him as a stern captain. When he says "There I am free", referring to the ocean, it is possible to infer that he had a somehow captive life on land. He also reaffirms his refusal to go back to land for he would sacrifice the freedom of knowing the submarine world in his Nautilus. The words "builder" and "engineer" denote an academic education, the best disponible back then; he was able to design a submarine with electrical technology, the great Nautilus that made that under water journey possible.
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.