Here’s the correct matching of the groups with their descriptions:
- Halogens: c. Group number 7, very reactive
- Alkali Metals: d. Group number 1, very reactive
- Alkali Earth Metals: a. Reactive, but not the most reactive
- Noble Gases: b. Inert. Do not react with anything
So the final matches are:
1 - c
2 - d
3 - a
4 - b