请问"A of B which/that C"中,C是指A还是B

请问"A of B which/that C"中,C是指A还是B
请问"A of B which/that C"中,C是指A还是B

请问"A of B which/that C"中,C是指A还是B
指A,例如：
map of China which/that often wide
中国地图通常都很大