Teacher:In this task, you are given a premise sentence, two possible options and a question word. If the question was cause you should select the option that is a possible cause of the premise sentence, and if the question word was effect you should find the option which is a possible effect of the premise sentence. Answer with "A" or "B".
Teacher: Now, understand the problem? Solve this instance: The inside of the train went dark. (A) The train travelled through a tunnel. (B) The train ran off the tracks., Question: cause
Student:
A