Al Brickett Had Two Mobile Homes on His Land Behind

Al Brickett had two mobile homes on his land behind his house. The mobile homes have been there since Al bought the land in 1971. In 1975, Al's area was zoned as R-1, an area for single family homes and no mobile homes. Al:

A) Is guilty of a felony.
B) Needs to obtain a variance.
C) Meets the requirements for a non-conforming use.
D) Can challenge the constitutionality of the restriction.