Answer
C.
Work Step by Step
C. is true, and B. is wrong because it is the opposite of C. A. was not found by Chargaff, and D. was a key part of the Watson-Crick model, which came after Chargaff's work.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.