Answer:
The correct answer is - blue and red both.
Explanation:
Codominance is the type of inheritance pattern in which alleles interact differently with one other. In this type of inheritance, neither allele is dominant or recessive and both traits are visible in the progeny if both alleles are present together in heterozygous conditions.
Here, in this case, Red frog and the blue frog are in codominance so the cross of these frogs leads to both colors that will be express in offspring together.
RR mate with BB
R R
B RB RB
B RB RB