Final answer:
To study the function of rods independently, scientists can study individuals with rod monochromacy or conduct experiments in complete darkness. Individuals with rod monochromacy only have functional rods, while in complete darkness, cones are inactive, allowing for isolated rod study.
Step-by-step explanation:
To study the function of rods alone, which can sense light about 1000 times dimmer than cones, one proposed method is option a) Study individuals with rod monochromacy. Rod monochromacy is a rare condition where individuals only have functional rods and no functioning cones, effectively granting an opportunity to examine rod function without the interference of cone activity. These individuals experience life solely through the sensitivity of rods, lacking color vision and having decreased visual acuity. Studying these individuals can provide insights into the capabilities and limitations of rods in isolation. Option c) Conduct experiments in complete darkness, could also be theoretically considered because in the absence of light, cones are inactive, and the rods alone are responsible for any visual perception. However, complete darkness eliminates all visual stimuli, making this a less practical method.