Two Chemicals, a and B, Are Combined, Forming Chemical C

Multiple Choice

Two chemicals, A and B, are combined, forming chemical C. The rate of the reaction is jointly proportional to the amounts of A and B not yet converted to C. Initially, there are 200 grams of A and 300 grams of B, and, during the reaction, for each gram of A used up in the conversion, there are three grams of B used up. An experiments shows that 75 grams of C are produced in the first ten minutes. After a long period of time, how much of A and of B remains, and how much of C has been produced?

A) 200 grams of A, 0 grams of B, 300 grams of C
B) 0 grams of A, 0 grams of B, 500 grams of C
C) 100 grams of A, 0 grams of B, 400 grams of C
D) 0 grams of A, 100 grams of B, 400 grams of C
E) 0 grams of A, 200 grams of B, 300 grams of C