If the Reaction Given Below Occurs and Pure a and B

Multiple Choice

If the reaction given below occurs and pure A and B were mixed, which of the following would take place as equilibrium was established?
A + B C

A) The concentration of C would increase for a time, then remain constant.
B) The concentration of A would increase for a time, then decrease.
C) The concentration of B would increase for a time, then remain constant.
D) Both a and c will occur.