Which one of the following is an example for polygenic inheritance?

With respect to height of human beings, we just don't have short and tall people but have people with lot of variation in their heights. It indicates that the character is influenced by more than two genes. Hence, it is described as polygenic inheritance.Blood grouping is co-dominance pattern of inheritance.Flower colour in Snapdragon is incomplete dominance pattern of inheritance.Phenylketonuria is pleiotropic pattern of inheritance in which single gene product can influence more than one characters.