complete the following statement of congruence

Answer:
Option A. Triangle STR
Step-by-step explanation:
we know that
If two triangles are congruent, then the corresponding sides and the corresponding angles are congruent
In this problem
If the two triangles of the figure are congruent
then
the corresponding sides are
MN and RS
NO and ST
MO and RT
and the corresponding angles are
∠N≅∠S
∠O≅∠T
∠M≅∠R
therefore
NOM≅STR