KINDLY NOTE that the compound in the question is attached below as a picture.
From the diagram in the picture, the compound contains an aryl group, Amine functional group and a carboxylic functional group. An Amino acid compound is a compound that has carboxyl group and the amine group which makes the answer to the question to be option 'b' that is Amino acid.
Polystyrene has formula like this:(C8H8)n, there is no amine functional group attached and there is no carboxyl functional group either which makes polystyrene not to be the answer. This the same case with vitamin D which has which has hydroxyl functional group and not carboxylic nor does it has amine functional group. Although it has been revealed through series of researches that Amino acid are good solvent for Carbondioxide, the most correct option for this question will be on identifying the correct compounds with reference to their functional groups.
Weight gain, trouble sleeping, anxiety, depression, headaches, GI problems like constipation and diarrhea, easy bruising, muscle weakness and increases cholesterol, and blood pressure.