Correct choice is (b) Glutamate
For explanation I would say: Acidic amino-acids are the one which have carboxylic groups as their side chains. Such two acidic amino acids ae aspartate and Glutamate. Basic amino acids are arginine, histidine and lysine. These contain ammonia as base in the side chains. Hence the name. When there is no extra acidic or basic group attaching as sidechains, the amino-acids are called neutral amino acids. Serine, Glutamine, threonine etc., are neutral amino acids.