The correct option is C to get
The infinitive verb is a verb with the word 'to' in front of it. This verb is always just a verb. There is no - ed, no - ing, no - s at the end of the verb. The verbs can be followed by questions words + To - infinitive. Thus, options B, C and D are wrong according to the rule. The correct option is A since 'to' is in front of the verb 'get' and verb 'tell' is followed by question word 'where' thus To-infinitive should be used.