Answer:
Incomplete dominance
Step-by-step explanation:
As mentioned in the question Snapdragons can have red, white, and pink colored petals. This is because snapdragon is such a plant which displays the phenomenon of incomplete dominance in flower petal colors. If the plant will have genotype RR, their petals would be red in color. If the genotype would be WW their petals would be white in color. However, if we cross a plant with red petals with a plant of white petals, the offspring plants will have flower with pink petals RW.
Why is this so?
This is because neither or red and white alleles are completely dominant over each other. Both give their own expression and the resultant color is therfore a blend of both parental colors. It can also be a reason that white could dilute the red and flower will get pink and incomplete dominance. As depicted in the figure attached, all the offspring will have pink trait in F1 generation.
Hope it help!