Final answer:
Opera seria describes a serious and dramatic style of Italian opera, with noble and classical themes, designed to elicit an intense emotional response from the audience.
Step-by-step explanation:
The phrase that best describes opera seria is b. Serious and dramatic opera. Opera seria is a style of Italian opera with noble, serious themes, often involving classical or mythological figures. It contrasts with opera buffa, which is light-hearted and comedic.
Opera seria is typically structured around arias with occasional ensemble pieces, and its tone is serious and dramatic rather than comic or light-hearted. The drama in opera seria is meant to evoke an intense emotional response from the audience, similar to how tragedy and melodrama operate in theater.