Answer: option B) used for energy
Explanation:
Amino acids are metabolized first by being deaminated (amino group, NH3 removed) leaving a carbon-containing compound as product.
This product then enters the citric acid cycle to yield energy in form of ATP and/or reducing equivalents like NADH, FADH.
A good example is Glutamic acid, that yields α-keto glutarate when the amine group is removed. This α-keto glutarate is directed to the CITRIC ACID CYCLE for ENERGY production.
So, the carbon-containing component of amino acids can be used for energy