What assumption is being made if scientists conclude that aspartic acid was formed by the prebiological synthesis in the passage?
a. aspartic acid is unstable at temperatures below 150°c.
b. all of the malic acid underwent the dehydration reaction to form fumaric/maleic acid.
c. compound a and cyanide were available on primitive earth.
d. the reaction between ammonia and fumaric acid was catalyzed by the presence of water.

A. Aspartic acid is unstable at temperatures below 150°C.

Explanation:

Aspartic acid  is an amino acid that is used in the production of proteins within  living cells.  It contains an amino group and a carboxylic acid, and can be synthesized by the body. It is a non-essential amino acid. The prebiological formation of aspartic acid occured at a certain temperature range. It was deduced from the passage that aspartic acid is unstable at temperatures below 150°C. The transamination of oxaloacetate in the human body gives rise to the formation of aspartate which is facilitated by the enzyme, aminotransferases. Aspartate also play a major role in the formation of urea by acting as a metabolite.