Answer:
B. Heterozygotes, dominant
Step-by-step explanation:
As given pure bred purple plant is crossed with pure bred white flower, their resulting flowers are all purple, it shows that purple is dominant over white.
So let purple as PP and white as pp
cross between PP and pp
PPĂ—pp ; their gametes are Parent-1: P , parent -2, p
Offspring are: Pp, Pp, Pp, Pp
Here all offspring are heterozygous and the allele for purple color is dominant over white color.