Brandon Has Blue Eyes,even Though Both His Mother and Father

Brandon has blue eyes,even though both his mother and father have brown eyes.What do we know about Brandon's parents?

A) At least one of his parents has a recessive blue-eye colour gene.
B) Each of his parents must have one recessive blue-eye colour gene.
C) Each of his parents must have one dominant blue-eye colour gene.
D) Neither of his parents has a blue-eye colour gene.