Why does the SMC curve cut the AVC curve at the minimum point of the AVC curve?

Explanation

Relation between MC and AVC:
1. MC and AVC are the same at the first unit of output
When AVC falls, MC is below AVC
3. When AVC rises, MC is above AVC
4. It is when AVC is minimum, MC = AVC or MC curve passes through the minimum of AVC curve (Point E).