An inducer a. inhibits the synthesis of the needed enzyme(s). b. stimulates the synthesis of the needed enzyme(s). c. binds to the promoter and prevents the repressor from binding to the operator. d. binds to the operator and prevents the repressor from binding at this site. e. binds to the termination codons and allows protein synthesis to continue.

An inducer (b) stimulates the synthesis of the needed enzyme.

Explanation:

A repressor is bound to the operator in the DNA chain inhibiting the synthesis of a needed enzyme. When the inducer binds to the repressor, this one change its shape and as a result, the repressor is not bound to the promoter anymore starting the synthesis of a specific enzyme.

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;