Answer:
B. R is dominant to r, and Rr individuals are red.
Explanation:
In genetics the dominant allele is represented by the uppercase letter and the recessive allele is represented by the lower case letter. A dominant allele always shows its dominance over the recessive allele. So in heterozygous condition dominant allele will reflects itself in the phenotype.
Here allele of red color allele is in capital letter and alleles of green color are shown in lower case which means R allele is the dominant allele and r is the recessive allele. Therefore R is dominant to r and in homozygous condition(Rr) red individual will be formed. So the right answer is B.