Hi there, I need help solving a proof.

I put all my answers in for the blank spaces, but number 4 I can't get. If someone could help that would be great. Thank you!

Given: Triangle SVX is congruent to triangle UTX and Line SV is parallel to line TU.

Prove: VUTS is a parallelogram.

Statement : Reason.
1. Tri SVX is congruent to Tri UTX. Reason: Given.

2. Line SV is parallel to line TU.
Reason: Given

3. Line SV is congruent to line TV.
Reason: CPOCTAC.

4. VUTS is a parallelogram.
Reason: ?

For number four, I'm not sure what the answer is. can anyone help?