Answer:
The correct option would be D) since plants grown in poor soil often need food to grow it is expected that bean plants given the most plant food will produce the most beans.
Step-by-step explanation:
A hypothesis can be described as a tentative statement which can be proved to be either right or wrong through scientific experiments.
Since the scientists wanted to test the effect of amounts of plant food on the number of beans produced hence the most suitable hypothesis would be " since plants grown in poor soil often need food to grow it is expected that bean plants given the most plant food will produce the most beans."
Other options like option A are not correct because option A refers to the eight of the plant whereas we want to observe the number of beans.