Question #N486

When the teacher asked, "What is the capital of France?" the students all shouted "Paris!" in unison. The teacher smiled, pleased with their enthusiastic response, and began to discuss the history of the city.

Which choice most effectively combines the sentences at the underlined portion to create a grammatically correct and stylistically appropriate sentence?
A. The teacher smiled, and pleased with their enthusiastic response began to discuss the history of the city.
B. The teacher smiled, pleased with their enthusiastic response, and began to discuss the history of the city.
C. The teacher smiled, being pleased with their enthusiastic response, and began to discuss the history of the city.
D. The teacher smiled, having been pleased with their enthusiastic response, and began to discuss the history of the city.