What term describes a many-voiced texture where different melodic lines are set one against another?

You find yourself in an English public theatre, watching an opera being staged with Italianate scenic conventions. You know at once that the year must be:

a. between 1576 and 1590 b. between 1590 and 1616 c. between 1616 and 1625 d. between 1625 and 1642 e. between 1642 and 1660

The introductory orchestra piece of an opera is called the

A. oratorio. B. introit. C. overture. D. prelude.