The hypothesis that the bacterial cultures from the deep surfaces produce magnetite and perform cellular respiration is supported by the evidence that:

• A. Bacteria treated with drugs that inhibit enzymes of the electron transport chain failed to produce magnetite
• B. Bacteria treated with drugs that inhibit enzymes of the electron transport chain produced more magnetite
• C. Bacteria that produce magnetite use iron in photosynthesis
• D. All of above

Answer: (A)