Here are the matches between the groups in Column A and their descriptions in Column B:
- Halogens: b. Group number 7, very reactive
- Alkali Metals: d. Group number 1, very reactive
- Alkali Earth Metals: c. Reactive, but not the most reactive
- Noble Gases: a. Inert. Do not react with anything
So the final matches are:
- 1 - b
- 2 - d
- 3 - c
- 4 - a