Abiologist working in a lab adds a compound to a solution that contains an enzyme and its substrate. this compound binds to the enzyme and decreases the rate at which the enzyme converts substrate to product. this decrease cannot be overcome by increasing the concentration of substrate to the reaction mix. therefore, which of the following is true of the compound?

a. the compound is an allosteric activator.
b. the compound is an allosteric inhibitor.
c. the compound is an inhibitor that binds to the active site of the enzyme.
d. the compound is a catalyst for the reaction.