The figure given below shows three velocity-substrate concentration curves for an enzyme reaction. What do the curves a, b and c depict respectively?
a-normal enzyme reaction, b-competitive inhibition, c-non-competitive inhibition
a-enzyme with an allosteric modulator added, b-normal enzyme activity, c-competitive inhibition
a-enzyme with an allosteric stimulator, b-competitive inhibitor added, c-normal enzyme reaction
a-normal enzyme reaction, b-non-competitive inhibitor added, c-allosteric inhibitor added