According to ADA specification of toothbrush width of brush head should be:: (A) 5/8-3/8inches., (B) 5/16-3/8inches., (C) 5/8-3/16inches., (D) 5/16-3/16inches.
Answer is B. Length of brush head: 1-1.25 inches.
Width of brush head: 5/16-3/2 inches.
Bristles: 2-4 rows.
Tufts in a row: 5-12 tufts