631190-12-31P AID: 2498 | 25/08/2015
The variation in the eye color phenotype is because white gene is inactivated in the white sectors due to the spread of heterochromatin. Genes present in the heterochromatin are silenced, and thus their expression is inhibited. And one more reason is the white gene is inactive in the white sectors and active in the red sector, resulting in the mixture of red and white color eyes.
Hence, the correct option is (d) b and c both are true.