The Bank Lending Channel of a Credit Crunch Is When

The bank lending channel of a credit crunch is when

A) bank restrict credit and so all firms find it hard to borrow
B) banks restrict credit and so small and medium size firms in particular find it hard to borrow
C) banks continue to lend, but borrowing through financial markets is restricted
D) borrowing is restricted though falling collateral values
E) Central Banks tighten credit conditions too much