For multiple choice questions in the listening test, try to underline just one or two keywords in each choice before the recording starts. It's much easier to focus on the difference between each choice if you've underlined the right keywords. Here's an example (from Cambridge IELTS 10):
What helped Rob to prepare to play the character of a doctor?
A) the stories his grandfather told him
B) the times when he watched his grandfather working
C) the way he imagined his grandfather at work
Transcript of Rob speaking:
I have to write about the role I played, the doctor, how I developed the character. My grandfather was a doctor before he retired, and I just based it on him. He must have all sorts of stories, but he never says much about his work. I'd visualise what he must have been like in the past, when he was sitting in his consulting room listening to his patients.
Notice that all three choices (A, B and C) are about the grandfather, so the keywords that I underlined are stories, watched and imagined. Which is the right answer?