Answer:
A) March
Step-by-step explanation:
As we can see in the graph above, the population of bacteria had a sharp drop in size in March, which means that the resources necessary for the development and maintenance of the life of this population of bacteria were limited or even scarce. So many bacteria ended up dying, which reduced the size of its population.
However, as time went by, the amount of resources increased and the population started to grow again.