Final answer:
Fleas in an occupied home typically emerge from their cocoons within 3-5 days when they sense vibrations, carbon dioxide, or body heat from a host. Option a.
Step-by-step explanation:
Fleas in an occupied home have certain life cycle stages including egg, larva, pupa (cocoon), and adult. Fleas will emerge from their cocoons when the conditions are favorable, which in an occupied home, is typically when they sense a host's vibrations, carbon dioxide, and body heat.
Although the exact time it takes for a flea to emerge from its cocoon can vary based on environmental factors, a common estimate for emergence in an occupied home is 3-5 days once they detect these cues. Flea development is affected by factors such as temperature, humidity, and the presence of a potential host.
Therefore, a flea cocoon in an occupied home where these stimuli are continually present might prompt a flea to emerge on the shorter end of that scale.
So Option a is correct.