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

Presence of allolactose represses the lac operon, while presence of tryptophan activates the trp operon.

Both operons are activated in the absence of their respective regulatory molecules.

Presence of allolactose activates the lac operon, while presence of tryptophan represses the trp operon.

Both operons are repressed in the presence of their respective regulatory molecules.