Knewton SC question 1

[reply2spg]

The 500,000 types of proteins in the human body are constructed from just twenty different amino acids, each amino acid a simple structure with its own distinct shape.

(A) each amino acid a simple structure with its
(B) all the amino acids simple structures with their
(C) all the amino acids a simple structure with its
(D) every amino acid a simple structure with their
(E) each amino acid a simple structure with their

OA A I got it right, but what is the difference between A and B?

[neoreaves]

In my opinion the difference is between describing the individuality of the amno acids and how each has a distinct shape .....its more to stress how each amino acid has a simple structure and distinct shape ...."all" would be used in this case to describe a quality that is the same across the whole group instead of each individual ...