Final answer:
To prove BC = EF, we can substitute the given values and express BC in terms of the given values. The correct answer is D) BC = EH + GC.
Step-by-step explanation:
Given BG = EH and GC = HF, we need to prove BC = EF.
Using the given information, we can rewrite BG and GC as EH and HF respectively.
By substituting these values into the equation BC = BG + GC, we have BC = EH + HF.
Therefore, the correct answer is D) BC = EH + GC.