One of the following is not a flower
Shoe flower
Passion flower
Sunflower
May flower
C.
Sunflower
Sunflower is not a flower due to the fact because its ray florets lack either of the male and female gametes , Stamens and Pistils. Therefore , its a neuter flower and has lost its ability to perform sexual reproduction.But in reality the real flower is the brown patches present on the inner sides.