Amino Acids

Step 1: Meaning of -amino acid.
In -amino acids, the amino group is attached to the terminal carbon atom farthest from the carboxyl group.

Step 2: Structure of caproic acid.
Caproic acid is hexanoic acid, having six carbon atoms.

Step 3: Position of amino group.
For -amino caproic acid, the –NH group must be attached to the terminal carbon, giving the structure:

Step 4: Conclusion.
Option (A) correctly represents -amino caproic acid.