Answer: The correct answer is- C.) several different genes control height.
As per the information given in the question, there are different plant heights in the population that is tall, short, and heights in between these two.
This indicates that this trait is controlled by many different genes ( as many different phenotype are seen in the population).
This situation corresponds to polygenic inheritance, which means that a particular characteristic of an organism is controlled by more than one two genes ( such as skin color, height in human beings)