Which of the following is NOT a typical negative bond covenant?

A) The firm must limit dividend payments.
B) The firm cannot merge with another firm.
C) The firm cannot issue additional long-term debt.
D) The firm cannot allow its bond rating to fall below its initial level.
E) The firm cannot pledge any assets to other lenders.

Negative bond covenants are designed to protect bondholders by limiting the actions of the borrower that could undermine the firm's financial stability or the bond's value. A typical negative covenant might restrict dividend payments, mergers, additional debt issuance, or pledging assets to other lenders to ensure the company maintains a certain level of financial health and does not undertake excessive risk that could jeopardize its ability to repay the bondholders. However, a covenant that prevents a firm's bond rating from falling below its initial level is not typical because bond ratings are determined by external agencies and can fluctuate based on a variety of factors beyond the firm's immediate control, such as changes in the economic environment or industry-specific risks.