Choose the underlined word or phrase, A, B, C or D that needs correcting

Choose the underlined word or phrase, A, B, C or D that needs correcting.

1. Having leisure activities are truly important to the elderly.

       a                                    b                           c           d

2. Collecting coins is exciting, but it can also be relaxed.

               a                b      c                                        d
3. When you game online, be carefully when making friends with strangers.

                         a                         b                         c                   d

4. Countryside is not polluted, because you can breathe fresh air there.

                        a                            b                            c                      d

5. I want to visit the Vietnam Museum of Ethnology to learn for 54 ethnic minority groups.

                  a                                           b                      c          d