Based on this excerpt, which of the following does the author describe as a drawback of using biomass generators?
A) Biomass generators are dangerous because they are used to burn large amounts of fuel.
B) Biomass generators produce less energy than other types of generators.
C) Biomass generators need a lot of organic material which can be expensive.
D) Biomass generators often result in pollution of nearby water sources.
The correct answer is C) Biomass generators need a lot of organic material which can be expensive.
Explanation: This option identifies a specific drawback related to the cost and availability of the organic materials required for biomass generation. If the author highlights the expense involved in sourcing sufficient organic materials, it would indicate a significant limitation in using biomass generators, especially in comparison to other energy sources that may not have such a requirement.