The level of competition between species depends on

Options

A. availability of resources,
B. population density.
C. group interaction of organisms.
D. All of the above

Answer

### Step-by-Step Solution:

1. **Understanding Competition**: Competition between species is an interaction where both species are negatively affected. It occurs when two or more species require the same limited resources, such as food, water, or shelter.

2. **Types of Resources**: The resources that species compete for can be categorized mainly into two types:
- **Food**: Essential for survival and growth.
- **Shelter**: Necessary for protection and breeding.

3. **Availability of Resources**: The level of competition is heavily influenced by the availability of these resources.
- **Abundant Resources**: If resources are plentiful, competition is minimal or non-existent, as each species can access what they need without conflict.
- **Limited Resources**: When resources are scarce, competition intensifies. Species must compete for the limited food or shelter available, leading to negative impacts on one or both species involved.

4. **Population Density**: The density of the population also plays a crucial role in competition.
- **High Population Density**: In areas where the population density is high, the competition for resources increases because more individuals are vying for the same limited resources.
- **Low Population Density**: Conversely, in areas with low population density, competition is less intense as there are fewer individuals competing for the same resources.

5. **Dominance Hierarchies**: In competitive interactions, one species may become dominant over another. The dominant species can suppress the growth or survival of the less dominant species, further influencing competition dynamics.

### Summary:
The level of competition between species depends on the availability of resources (food and shelter), the population density of the species involved, and the presence of dominant species that can suppress others.

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