Abrasion of enamel and root surfaces may result from the long term use of.. Vigorous use of the toothbrush

Abrasion of enamel and root surfaces may result from the long term use of:
1. A hard toothbrush.
2. Tooth abrasive toothpaste or powder.
3. Vigorous use of the toothbrush.
4. A and B only.
5. A, B and C. ***