Which of the following statements best describes a credit curve roll-down strategy?

A. Returns from a credit curve roll-down strategy can be estimated by combining the incremental coupon from a longer maturity corporate bond with price appreciation due to the passage of time.

B. A synthetic credit curve roll-down strategy involves purchasing protection using a single-name CDS contract for a longer maturity.

C. A credit curve roll-down strategy is expected to generate a positive return if the credit spread curve is upward sloping.