Which one of the following statements is TRUE?

a$.$

A lender calling in a corporate loan and then lending the funds out to a safer borrower is an example of asset switching.

b$.$

Firms borrowing money have greater flexibility to use that money when there are debt covenants.

c$.$

When lenders protect themselves from the risk of asset switching by raising the interest rate, the firm's WACC can decrease.

d$.$

A supplier substituting a lower$-$quality raw material without approval is an example of asset switching.

e$.$

An agency problem occurs when an owner$/$manager sells stock to an outsider but continues to consume perquisites.