During a normal chewing cycle, which of the following has/have maximum EMG activity when the teeth are in maximum intercuspation?
1. Medial pterygoid muscles.
2. Masseter muscles.
3. Lateral pterygoid muscles.
4. Digastric muscles.

(1) (2) (3)

(1) and (3)

(2) and (4)

(4) only

All of the above.