Answer:
Heterozygous
Step-by-step explanation:
Let's assume that the allele R gives red flowers while the allele "r" gives white flowers. The genotype of the pure breeding plants with red flowers will be "RR" and that of the pure breeding plants with white flowers will be "rr". The "RR" plant will form all the gametes with one copy of "R" allele only. The "rr" plant will produce all the gametes with one copy of "r" allele only. The fusion of gametes with "R" and "r" alleles will form all the progeny with "Rr" genotype. The phenotype of the progeny will be pink. Since "Rr" genotype has one dominant and one recessive allele, it is heterozygous.