What does the term electron orbital describe?

Question

A. An electron orbital describes the exact distance of an electron from the nucleus.
B. An electron orbital describes the orbit of an electron around the nucleus.
C. An electron orbital describes a three-dimensional space where an electron can be found 90% of the time.

Answer 1

C. An electron orbital describes a three-dimensional space where an electron can be found 90% of the time.

This is the most accurate description of what an electron orbital represents in quantum mechanics. It does not refer to a fixed path or exact distance from the nucleus, but rather a probabilistic region in which an electron is likely to be found.