The correct option is B. Reduction of habitat space due to urban development. Detailed Explanation Carrying Capacity Defined: Carrying capacity refers to the maximum number of individuals of a particular species that an environment can sustainably support over time. This capacity is influenced by various factors, including food availability, habitat space, water supply, and competition for resources. Why Option B is Correct: 1. Habitat Space Reduction: Urban development often leads to the destruction or alteration of natural habitats. When habitats are reduced, the available space for organisms to live, find food, and reproduce diminishes. This directly impacts the population size that the environment can support.

1. Resource Availability: With less habitat, there are fewer resources (like food and shelter) available for the organisms. This can lead to increased competition among individuals for the limited resources that remain, which can further decrease the population size.
2. Fragmentation: Urban development can also fragment habitats, isolating populations and making it difficult for individuals to find mates, which can lead to decreased genetic diversity and increased vulnerability to extinction.

Why the Other Options are Incorrect or Weaker: A. Increased availability of food resources - Explanation: Increased food availability typically leads to an increase in a population's carrying capacity. More food means that more individuals can survive and reproduce, thus supporting a larger population. This option does not lead to a decrease in carrying capacity; rather, it enhances it. C. Decreased competition for resources - Explanation: If competition for resources decreases, it usually means that individuals have better access to the resources they need to survive and reproduce. This can lead to an increase in population size, as more individuals can thrive without the stress of competing for limited resources. Therefore, this option does not contribute to a decrease in carrying capacity. D. Improved reproductive rates of the species - Explanation: Improved reproductive rates would generally lead to an increase in population size, as more offspring are produced. This would not decrease the carrying capacity; instead, it could push the population closer to or even beyond the carrying capacity if resources are not sufficient to support the increased numbers. Summary of Key Points:

• Carrying Capacity: The maximum population size an environment can sustain.
• Correct Answer (B): Urban development reduces habitat space, leading to decreased carrying capacity.
• Incorrect Options:
• A (Increased food) and D (Improved reproduction) both increase carrying capacity.
• C (Decreased competition) allows for population growth, not a decrease in capacity.
• Impact of Habitat Loss: Urbanization leads to resource scarcity, increased competition, and potential population decline.

This understanding of carrying capacity and the factors that influence it is crucial for ecology and conservation efforts, as it helps predict how populations will respond to environmental changes.