Answer:
C. DC = DC. By reflexive property of equality.
Step-by-step explanation:
We are given that,
In step 4, Jimmy proved ΔADC ≅ ΔBCD by the SAS Congruence Postulate.
For that, the previous steps states,
Step 1: AD = BC, as opposite sides of a rectangle are congruent.
Step 2: ∠ADC = ∠BCD
So, in order to satisfy the SAS Postulate, we must have another pair of sides equal from the respective rectangles.
As, we can see that in ΔADC and ΔBCD, the side DC is a common side.
Thus, in the missing step, we get,
Step 3: DC = DC, By the reflexive property of equality.
Hence, option C is correct.
