TOEFL Reading: ETS-TOEFL阅读机经 - 5X61CF36O2533281L$

Why does the author include the statement "Treat a colony of these termites with an antibiotic solution, and they will slowly starve to death" A. To suggest one reason why termites sometimes leave a colony B. To emphasize how dependent the termites are on bacteria C. To account for the elimination of certain termite lineages D. To help explain why termites protect essential microorganisms by carrying them in their stomachs