As a result of the ground-breaking work of Barbara McClintock, many scientists now believe that all of the information encoded in 50,000 to 100,000 of the different genes found in a human cell are contained in merely three percent of the cell's DNA.

(A) 50,000 to 100,000 of the different genes found in a human cell are contained in merely
INCORRECT; we need singular verb "is"

(B) 50,000 to 100,000 of the human cell's different genes are contained in a mere
INCORRECT; we need singular verb "is"

(C) the 50,000 to 100,000 different genes found in human cells are contained in merely
INCORRECT; we need singular verb "is"

(D) 50,000 to 100,000 of human cells' different genes is contained in merely
INCORRECT; we need adjective "mere" to modify noun

(E) the 50,000 to 100,000 different genes found in a human cell is contained in a mere