What makes a line one of the key elements of art

A line is basically the foundation of anything when you draw something. It ranges from straight, curved, etc.

Explanation:

I had art in my Freshman Year. Most boring teacher that taught it, but he always complained about lines not be lines, and how a line was a line, and why lines are so important to get right. It's just engrained in my head even though it will never even help me in my life at all.

answer; i believe the correct answer is (proximity);