Question

protozoan cysts ____________. multiple choice are part of all protozoan life cycles are necessary for transmission to a new host are helpful in surviving unfavorable conditions

Explanation:

Protozoan cysts are protective forms that allow protozoa to survive in harsh or unfavorable environmental conditions such as lack of nutrients, extreme temperatures etc. Not all protozoans have cysts in their life - cycles, and while they can be involved in transmission, they are not always necessary for it.

Answer:

C. are helpful in surviving unfavorable conditions