Answer: Mandates the issuer to maintain a standby credit facility.

**Explanation:** - **Option A** is incorrect because commercial paper is an unsecured short-term debt instrument, meaning issuers are not required to pledge collateral. - **Option B** is correct. Credit rating agencies typically require issuers of commercial paper to secure a backup line of credit from banks to ensure liquidity and reduce default risk. - **Option C** is incorrect. While commercial paper is short-term, its maturities generally do not exceed 270 days, not two years.

Author: LeetQuiz Editorial Team