Sandra calculated the missing side length of one of these triangles using the Pythagorean Theorem. Which triangle is it?

Four triangles A, B, C, D are shown from left to right. Triangle A has two sides labeled 6 each, and the included acute angle is shown. Triangle B has one side labeled as 2 and the other as 3, and the included obtuse angle is shown. Triangle C has one side labeled as 6 and the other as 7, and the included acute angle is shown. Triangle D has one side labeled as 2 and the other as 3, and the included right angle is shown.

A
B
C
D