In an incomplete dominance pattern, the phenotype of the heterozygous offspring is a mix of the phenotypes of the two homozygous parents. In this case, we have:
- Homozygous red carnation (RR)
- Homozygous white carnation (rr)
When these plants are crossed, the offspring will have the following genotypes:
- All offspring will be Rr (heterozygous).
In incomplete dominance, the R allele (red) and the r allele (white) combine to produce a third phenotype, which is a blend of the two colors. Thus, the Rr genotype will result in pink flowers.
Based on this information, the correct answer is B. only pink flowers.