What experimental setup did Lazzaro Spallanzani use that contributed to refuting spontaneous generation?

• A. Heating infusions were sealed tightly after boiling until they were sterile.
• B. Keeping infusions at body temperature under normal atmospheric conditions.
• C. Exposing infusions continuously to UV light.
• D. Allowing infusions to remain unsealed at room temperature alongside controlled samples sealed post-boiling.

Answer: (A)