In the context of variations of dominance, what best defines a recessive allele?

• A. An allele that is always expressed whenever it is present, even in a heterozygote
• B. An allele whose phenotype is masked in a heterozygote by a dominant allele and typically expressed only in a homozygote
• C. An allele that is expressed only in males because it is located on the $Y$ chromosome
• D. An allele that produces an intermediate (blended) phenotype in heterozygotes due to incomplete dominance

Answer: (B)