If both parents are heterozygous for Huntington's Chorea (Hh), there is a 75% chance that their child will inherit the disease. This conclusion is derived from a Punnett square calculation. Thus, the answer is D. 75%.
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Both parents with Huntington's Chorea, being heterozygous, can have a child who is 75% likely to inherit the disease. This is derived from using a Punnett square to analyze the genetic combinations. Therefore, the correct answer is D. 75%. ;