Final answer:
An ideal free distribution may not be achieved due to predators, territoriality, and variations in the population's genes. The competitive exclusion principle further explains why species distribute unevenly as they cannot occupy the same niche within a habitat. The correct option is c.
Step-by-step explanation:
The concept of an ideal free distribution might not be achieved in nature due to a variety of factors. Option 'c', which mentions the presence of predators or territoriality may preclude free movement between habitats, is a valid reason why an ideal free distribution can be inhibited.
Predators can directly impact the ideal free distribution by creating zones of danger, which individuals may avoid, even if resources are abundant. Territoriality also limits access to resources as some individuals defend areas that contain valuable resources, excluding others from exploiting the area to its full potential.
Variations in genes among a population (option 'c') can lead to different abilities among individuals in recognizing and utilizing resources, also contributing to deviations from the ideal free distribution. The correct option is c.