It's always useful to check the transcripts at the back of the Cambridge IELTS books after you've done a practice test. This is especially helpful when you've done a multiple choice exercise.
Here's an example from Cambridge IELTS 10, page 35:
What decision has not yet been made about the pool?
A) whose statue will be at the door
B) the exact opening times
C) who will open it
Here's the relevant part of the transcript:
We're on schedule for a June 15th opening date and well within budget. We have engaged award-winning actress Coral White to declare the pool open and there'll be drinks and snacks available at the pool side. There'll also be a competition for the public to decide on the sculpture we plan to have at the entrance; you will decide which famous historical figure from the city we should have.
Can you see what the correct answer is, and explain why? Which 'keywords' gave you the answer? Also, can you see that all three choices are mentioned?