Answer: Acceleration
Explanation: Acceleration clause is a contract provision, between a lender and a borrower,in this case the lender requests that the borrower pay his remaining loan which is due and mature for payment,when the borrower fails to meet some or all of the loan conditions. Acceleration clause is mainly applied in Real Estate and it helps both parties to avoid any legal consequences that may emanate from any breach especially by the Borrower. The mail received by Parker informing him to make immediate payment for his loan is an example of an application of ACCELERATION CLAUSE.