The correct option is C The heavy door shut behind me as I walked into the room.
Adjectives that are placed right before the noun/noun phrase it
modifies are attributive adjectives.
Option C is correct because the adjective "heavy" precedes the noun "door" that it modifies. The adjective here is attributive in nature.
Option A is incorrect because, even though the adjective is correctly placed before the noun "room", it makes no sense; a room can't be called heavy.
Option B is incorrect because attributive adjectives do not immediately follow the nouns that they modify.
Option D is incorrect because the answer lies in C.