This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Non essential amino acid - aspartate is synthesized by which reaction in the body? 
Select and explain. 
A. Transamination from pyruvate, B. Transamination from oxaloacetate, C. Transamination from α-ketoglutarate, D. Removal of hydroxymethyl group from serine
B: Transamination from oxaloacetate
Answer: B: Transamination from oxaloacetate 
Explanation: Nonessential amino acids—can be synthesized in humans.
a. Alanine—transamination from pyruvate.
b. Aspartate—transamination from oxaloacetate.
c. Asparagine—addition of ammonia to aspartate.
d. Cysteine—skeleton from serine and sulfur from methionine.
e. Glutamate—transamination from α-ketoglutarate.
f. Glutamine—addition of ammonia to glutamate.