Which sets of side lengths could form a triangle?
A. 3 centimeters, 4 centimeters, 9 centimeters
B. 3 centimeters, 6 centimeters, 9 centimeters
C. 4 centimeters, 5 centimeters, 9 centimeters
D. 4 centimeters, 6 centimeters, 9 centimeters