1. The problem asks which congruence criterion applies to the two triangles sharing side $PQ$ with vertices $N, O, P$ (top triangle) and $N, Q, P$ (bottom triangle). 2. The top triangle $NOP$ has a right angle at $N$, and the bottom triangle $NQP$ shares side $PQ$ with the top triangle. 3. Both triangles have two sides marked with one dash each, indicating those sides are equal in length. 4. To determine congruence, recall the common criteria: - SSS (Side-Side-Side): all three sides equal - SAS (Side-Angle-Side): two sides and the included angle equal - ASA (Angle-Side-Angle): two angles and the included side equal - AAS (Angle-Angle-Side): two angles and a non-included side equal 5. Since the triangles share side $PQ$, that side is equal in both. 6. The right angle at $N$ in the top triangle corresponds to an angle in the bottom triangle at $N$ as well, so one angle is equal. 7. The two sides marked equal correspond to $NP$ and $NQ$ or $NO$ and $NQ$ depending on labeling, but since the problem states two sides marked equal, and one angle (right angle) is included between those sides, the criterion is SAS. 8. Therefore, the triangles are congruent by SAS. Final answer: B They are congruent by SAS.