Context: Below is a food web from Little Rock Lake, a freshwater lake ecosystem in Wisconsin.
A food web models how the matter eaten by organisms moves through an ecosystem. The arrows in a food web represent how matter moves between organisms in an ecosystem.
Which of the following organisms is the decomposer in this food web?
A. black crappie
B. bacteria
C. rotifer
From the given choices, select the correct answer and reply with the letter of the chosen option.

B