An obligation imposed by law where there has been no agreement or expression of assent by word or act on the part of either party involved is a(n) :

A) implied in fact contract.
B) express contract.
C) void contract.
D) quasi contract.

The described obligation is a quasi contract, which is not an actual contract but rather a legal remedy to prevent unjust enrichment. It is created by a court to impose an obligation on a party who has received a benefit without having an agreement or express assent with another party.