Answer:

A.  ΔDGH ≅ ΔFEH

Step-by-step explanation:

We are given the proof of GH ≅ EH and DH ≅ FH.

Now, previous to step 7, we have obtained,

Step 5: ∠HGD ≅ ∠HEF  and ∠HDG ≅ ∠HFE

Step 6: DG ≅ EF as opposite sides of a parallelogram are congruent.

Since, we have that two angles of the triangles are congruent and their including sides are also congruent.

Thus, by Step 7 i.e. ASA criterion for congruence, we get that the corresponding triangles are also congruent.

Hence, we get, ΔDGH ≅ ΔFEH.