B is going to be your answer
Answer:
Me encantaría ayudar, pero para decirte la verdad, yo mismo no lo entiendo.
Explanation:
When you use "por" or "para" your saying the word "for" so for example
enlgish: I need to go for a game
spanish:yo nesicito ir para un juego
so technically you use it when the sentence has the word "for" or the word is needed
