A loan in which the borrower arranges in advance with a mortgagee for a total amount that will be advanced, in stages, under the mortgage to meet the part of the costs of construction as it progresses is a$($n$)$:

A$.$

Nonrecourse mortgage.

B$.$

Assumption of the mortgage.

C$.$

Subordination of the mortgage.

D$.$

Open$-$end mortgage.