Answer:
C) Have you found out if the train left?
Step-by-step explanation:
Direct and indirect speech refers to the manner or way in which speeches are reported. The direct speech refers to the direct usage of the exact words spoken whereas an indirect speech is a changed, conformed way of stating or expressing what has been said. The indirect speech focuses more on the content of the speech that's reported rather than the exact words used in the reported speech.
The given direct question "Has the train left?" will be written in the indirect speech as "Have you found out if the train left?" The "has" in the direct speech will be changed to "have" in forming/ asking the question.
Thus, the correct answer is option C.