Which of the following best describes the altitude of a three-dimensional figure?
a. length
b. perimeter
c. height
d. area

option: c is the correct answer.

c.    height

Step-by-step explanation:

A altitude or height (or sometimes called as depth) is defined as a distance measurement usually in the vertical up direction between a reference point and a point or object.

Vertical distance measurements in the "down" direction are commonly referred to as depth.

Hence, height best describes the altitude of a three-dimensional figure.

Hence, option c is the correct answer.

we need more info to solve this