Astronomy major please help me

Question

Which of the following describes parallax?

Answer:

a. It is inversely proportional to an object's distance.

b. It is an ancient method of finding distances, no longer useful today.

c. It can be used only with the most remote objects in space.

d. It is a method of measuring the length of small objects, such as pencils.

Answer 1

A is the answer...  although I'm not crazy about the way the answer is worded.

Answer 2

the answer is A