Given below are two statements:

Assertion (A): Glycine must be taken through diet.
Reason (R): It is an essential amino acid.
 
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. Both (A) and (R) are False.