You have two true-breeding rose bushes, one with red flowers and one with white flowers. A cross between these two roses yields a rose bush with two-color flowers. Each flower is both red and white. This is an example of

A) codominance.
B) incomplete dominance.
C) environmental effects.
D) polygenic inheritance.
E) epistatic interaction.

In codominance, both alleles are expressed equally in the heterozygous condition. In this case, the red and white alleles are both expressed in the flower, resulting in a two-color flower. Incomplete dominance would result in a blending of red and white, producing a pink flower. Environmental effects, polygenic inheritance, and epistatic interactions do not apply to this scenario.