Which statement best describes the effect of regulatory molecules on the lac and trp operons?

• A. Presence of allolactose represses the lac operon, while presence of tryptophan activates the trp operon.
• B. Both operons are activated in the absence of their respective regulatory molecules.
• C. Presence of allolactose activates the lac operon, while presence of tryptophan represses the trp operon.
• D. Both operons are repressed in the presence of their respective regulatory molecules.

Answer: (C)