A mixture of carboxylic acids `(X)` and `(Y)` cannot be separated by normal methods however when this mixture is treated with optically active quinine give optically acitve salts `(P)` and `(Q)`. These two salts can be separated by fractional crystallization, separated and acidified with `HCl` to from amines and carboxylic acids.
What is the diastereoisomer of `(+)` - tartaric acid?
A. `(-)` - Tartaric acid
B. Maleic acid
C. meso-Tartaric acid
D. all of these
