Final answer:
The activity with the highest potential for aerosol exposure is not using safety caps on centrifuge buckets, as it can result in the generation of aerosols potentially containing infectious agents.
Step-by-step explanation:
The option with the highest potential for aerosol exposure is (a) Not using safety caps on centrifuge buckets. When centrifuge buckets are used without safety caps, the risk of generating aerosols from the contents is high. These aerosols can contain infectious agents and expose laboratory personnel to biological hazards, especially if the centrifuge experiences a malfunction or is improperly used. It's important to use all appropriate containment devices and procedures to minimize the chances of aerosol exposure.
Pipetting within a biological safety cabinet, as mentioned in option (c), is actually designed to minimize aerosol exposure, and therefore, when done correctly, should not pose a high risk. Using needle safety devices during phlebotomy and preventing sharps containers from being overfilled are also critical practices to reduce the risk of exposure to sharps and needlestick injuries, but these do not directly relate to aerosol generation.