A technician needs to position a sealed gamma source. She plans the task before removing the source from its shielded container and uses long tongs. How do these precautions reduce her exposure?
Planning reduces source activity; tongs increase distance from the source.
Planning reduces source activity; tongs shorten the source's half-life.
Planning reduces exposure time; tongs increase distance from the source.
Planning reduces exposure time; tongs shorten the source's half-life.