Question

anaerobic digestion of manure produces_________.
a) biogas
b) compost
c) ammonia
d) hydrogen sulfide

Explanation:

Anaerobic digestion is a biological process in which organic matter (like manure) is broken down by microorganisms in the absence of oxygen. One of the main products of this process is biogas, which is a mixture of methane, carbon dioxide, and small amounts of other gases. Compost is produced by aerobic decomposition (with oxygen). Ammonia and hydrogen sulfide are not the primary products of anaerobic digestion of manure in the context of what is typically emphasized for this process (biogas production is a key outcome often highlighted in educational and practical discussions about anaerobic digestion of such organic waste).

Answer:

A. Biogas