Correct Answer - D
In reductive amination in the presence of enzyme glutamate dehydrogenase and a reduced coenzyme (NADH or NADPH), ammonia can directely combine with `alpha`-ketoglutaric acid to from a an amino acid. On the other hand, transamination is transfer of amino group `(-NH_(2))` of one amino acid with the keto group (gt C=O) of keto acid. in transaminase, transfer of `NH_(2)` from glutamic acid takes place. The enzyme required is transaminase or aminostransferase.