To determine which statement is a valid conclusion based on the information about the reproductive rate of the bacteria across different pH levels, we need to focus on the definitions of the types of bacteria mentioned:
- Neutrophils: Bacteria that thrive in a neutral pH range (around pH 7).
- Acidophiles: Bacteria that thrive in acidic environments (typically below pH 7).
- Alkaliphiles: Bacteria that prefer alkaline environments (typically above pH 7).
- Thermophiles: Bacteria that thrive at high temperatures, which is unrelated to pH.
Given this information, if the graph shows a peak reproductive rate around neutral pH (pH 7), then the valid conclusion would be:
a. The bacteria are neutrophils.
If the peak is below pH 7, then b. The bacteria are acidophiles would be valid. If it is above pH 7, then c. The bacteria are alkaliphiles would be valid.
Since the question does not provide the specific details of the graph, I cannot definitively select one answer without that information. However, based on the definitions provided, you should be able to choose the correct conclusion based on the peak reproductive rate indicated in the graph.