Suppose Bianca Buys a Used a Textbook from Sebastian for $55

Multiple Choice

Suppose Bianca buys a used a textbook from Sebastian for $55. If Bianca's surplus from this transaction was $10, we can infer that:

A) Bianca's reservation price was $45.
B) Bianca's reservation price was $60, and Sebastian's reservation price was $50.
C) Bianca's reservation price was $65.
D) Sebastian's reservation price was $45.