Please answer the following Accounting question. Please explain.

With respect to RRSP contributions, which of the following statements is correct? a. Contributions made during the current year can be deducted in any subsequent year. b. Contributions in excess of available deduction room cannot be deducted in the current year or in any subsequent year. c. Contributions made during the current year and within 30 days of the end of the current year, must be deducted in the current year. d. There is no penalty for making contributions that are in excess of available deduction room