What action would allow officers to search a home even if they didn’t have a warrant?

A.
A spouse lets them into the house and tells them they can search it.
B.
The resident has been previously convicted of murder.
C.
The police have a strong feeling that the residents have committed a crime.
D.
A spouse has been previously convicted of murder.

A. A spouse lets them into the house and tells them they can search it.