Which of the Following Does NOT Affect the Enforceability of a Guarantee

Which of the following does NOT affect the enforceability of a guarantee?

A) the release by the creditor of security placed in support of the loan without the guarantor's approval
B) the absence of a note or memorandum signed by the guarantor
C) lack of consideration
D) the release of other guarantors by the creditor without the knowledge of the remaining guarantors
E) the death of the primary debtor