Answer:
The answer is C, so the sentence should be, "en mi país, hay varias razas y religiones." The word "varias" (various) is plural, and it matches in gender with razas and religiones.
A is incorrect because the "si" is "if," and this doesn't make much sense. (It also wouldn't be a complete sentence if you put "if.")
B is incorrect because it roughly means "must" or "one must." This phrase doesn't make much sense in the sentence because I think it would translate to "In my country, one must races and religions," which isn't a complete sentence.
D is incorrect because "razas y religiones" is plural (races and religions). The word "una" is singular, so it doesn't match with the plural razas y religiones.
