The type of teeth used for tearing in humans is the canines. Situated at the corners of the dental arches, these four sharp, pointed teeth are designed specifically to rip and tear tough food, particularly meat.

The dental formula for an adult human is (2.1.2.3) / (2.1.2.3), representing two incisors, one canine, two premolars, and three molars in each half of the upper (top) and lower (bottom) jaw, totaling 32 permanent teeth (including wisdom teeth).

The correct answer is option D