Answer:
Option A.
Step-by-step explanation:
Given: QRST is a parallelogram and M is the intersection of diagonals.
We know that opposite sides of a parallelogram are parallel and equal.
In △QMR and △SMT,
[tex]\angle MQR=\angle MST[/tex] (Alternate interior angles)
[tex]QR=ST[/tex] (Definition of parallelogram)
[tex]\angle QRM=\angle STM[/tex] (Alternate interior angles)
Two corresponding angles and included sides are congruent.
[tex]\triangle QMR=\triangle SMT[/tex] (ASA postulate)
Hence, the correct option is A.