Final answer:
Some offspring will be affected when an affected parent with an autosomal dominant, homozygous lethal condition mates with an unaffected parent.
Step-by-step explanation:
When considering a mating between an affected parent with an autosomal dominant, homozygous lethal condition and an unaffected parent, the correct outcome for the offspring would be that some offspring will be affected. This is because a heterozygote parent (carrying one dominant lethal allele and one normal allele) would produce offspring that are either unaffected carriers (heterozygous) or unaffected non-carriers (homozygous for the normal allele). Since the homozygous dominant condition is lethal, the affected parent must be heterozygous. As a result, when mating with an unaffected (homozygous recessive) parent, the expected ratio is that half of the offspring will inherit the dominant lethal allele and be affected, while the other half will not inherit this allele and be unaffected.