To facilitate in naval navigation, the Han Dynasty invented the
A. sailboat
B. magnetic compass
c. automated rudder
D.
astrolabe

To facilitate in naval navigation, the Han Dynasty invented the B. magnetic compass

Explanation:

The magnetic compass is one of the most important inventions of the ancient era which was achieved by the Han dynasty during their rule as they were trying to come up with ways for better naval networking for trade routes.

The Han dynasty was one of the greatest innovators of the ancient world with their great inventions ranging from Paper and the wheelbarrow to the magnetic compass. These great inventions often helped them establish the silk route and become a major point of trade on the globe.

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."

answer; martin seligman;