Mr X Executed a Chattel Mortgage Over His House and Lot

Mr. X executed a chattel mortgage over his house and lot to Mr. Y. When the obligation became due, Mr. X did not pay despite demand.

A) Mr. Y has no right to foreclose the mortgage because the house and lot are not chattels.
B) Mr. Y has no right to foreclose the mortgage unless Mr. X consents to the foreclosure.
C) Mr. Y has no right to foreclose the mortgage because he can sue for collection.
D) Mr. Y may foreclose the mortgage because Mr. X is estopped from claiming the invalidity of the chattel mortgage over the real property, but foreclosure should be made under the procedure of a real estate mortgage.