If only the dominant trait appears in the first generation, what is the correct conclusion about the recessive trait?

Correct answer: It remains hidden but is not lost

In a heterozygous individual, the dominant allele determines the visible phenotype and masks the expression of the recessive allele. Masking does not remove or transform the recessive allele; it remains part of the genotype and can be transmitted to offspring. If two recessive alleles later come together, the recessive phenotype can reappear, often in the F2 generation. Thus A is correct, while B, C and D misunderstand inheritance.