Answer: The correct option is (B) Congruent - SAS.
Step-by-step explanation: We are given to check whether triangle RST is congruent to the triangle XYZ.
If so, we are to state the postulate.
Given that, in ΔRST and ΔXYZ, we have
RS ≅ XY
ST ≅ YZ
and
∠S ≅ ∠Y.
That is, two sides and the angle between them of ΔRST are congruent to the corresponding two sides and the angle between them of ΔXYZ.
So, by SAS (side-angle-side) postulate, we get
ΔRST ≅ ΔXYZ.
Therefore,
the given triangles are congruent by SAS postulate.
Option (B) is CORRECT.