How can an offspring inherit a recessive trait?

a) an offspring can inherit a recessive trait if one of its parents has the trait and the other is homozygous for the dominant allele
b) an offspring can inherit a recessive trait if one of its parents is heterzygous for the recessive allele and the other is homozygous for the dominant allele
c) an offspring can inherit a recessive trait if both of its parents are homozygous for the dominant allele
d) an offspring can inherit a recessive trait if both of its parents are heterzygous for the dominant allele