Read the passage below and choose the letter A, B, C, or D to indicate the correct answer to each question from 18 to 22.

What’s the problem with British teenagers? Many British newspapers and TV programmes are asking this question at the moment. A lot of people are saying that there are problems with teenagers at school, on the streets and in their homes. Why? What, or who, is responsible for these problems? A recent BBC television series explores these questions. It's called 'The world's strictest parents'. Is that because British parents are very strict? Just the opposite, it seems. The director of the programme, Andrea Wiseman, explains why they are making it. She thinks that in the United Kingdom teenagers pay no attention to adults. They don't want to do well at school. They think they can do what they like and they are only interested in new fashions and Hollywood celebrities. Why are British teenagers like this? Wiseman says it's because their parents give their children everything they can. But they give their children no limits, no rules, no discipline because they want their children to be 'free'. They don't tell their children to work hard because they don't want their kids to have any stress. The problem with this is that parents give their sons and daughters no cultural values. When a teenager does something bad and their parents say something, the teenagers immediately say: 'My parents are really strict’ or 'My parents aren't fair'. So what happens in the TV programme? Some problematic British teenagers go and live with parents in different parts of the world. They live with families that believe in traditional discipline and cultural values. In Ghana, Jamaica, Botswana and the Southern US state of Alabama, the teenagers have the experience of living with parents who want and expect good behaviour and hard work. The results are interesting. In the end, the British teenagers seem to prefer having strict parents!

The word “explores” in the passage is closest in meaning to _______.