The correct option is
C any
In the given sentence, the subject needs some advice from the object. Here, 'advice' is a singular noun. Further, 'advice' is not something that can be given in a specific quantity(advice cannot be counted). Thus, the answer has to be an unspecific quantity that can be used with a singular noun.
Option A is incorrect. 'an' is used to indicate only a specific quantity and that is 'one'. Thus, it cannot be used along with 'advice'.
Option B is incorrect. 'a' is only used to indicate the quantity 'one' and also, it cannot be used when the word after it starts with a vowel. For these reasons, it is incorrect.
Option C is correct. 'any' indicates an unspecific quantity. It means 'whatever quantity available'. It indicates that the subject is asking the object for whatever amount of advice that the object can possibly give. Thus, it is correct.
Option D is incorrect. 'many' is also used to indicate unspecific quantity but, it can only be used with plural nouns. For example, many friends, many books and so on. Thus, it cannot be used here as 'advice' is a singular noun.