Under normal condition …….A……..and ………B……..are the most important factors influencing population density ……….C……..and ……..D……. Assuming importance only under special condition
Choose the correct option for A,B ,C and D

Options

A. A-mortality B-natality,C-emigration,D-immigration
B. A-immigration B-natality,C-emigration,D-mortality
C. A-emigration B-natality C-mortality ,D-immigration
D. A-emigration,B-immigration,C-mortality ,D-natality

Answer

To solve the question, we need to identify the factors A, B, C, and D that influence population density under normal and special conditions.

### Step-by-Step Solution:

1. **Identify Factors Influencing Population Density**:
- The factors that influence population density can be categorized into two groups: those that are significant under normal conditions and those that are significant under special conditions.

2. **Normal Conditions**:
- Under normal conditions, the two most important factors influencing population density are:
- **A**: Natality (the birth rate)
- **B**: Mortality (the death rate)
- Natality increases population density, while mortality decreases it.

3. **Special Conditions**:
- Under special conditions, the factors that become important are:
- **C**: Immigration (the arrival of individuals into a population)
- **D**: Emigration (the departure of individuals from a population)
- Immigration increases population density, while emigration decreases it.

4. **Final Identification**:
- Therefore, we can conclude:
- **A** = Natality
- **B** = Mortality
- **C** = Immigration
- **D** = Emigration

### Final Answer:
- A = Natality
- B = Mortality
- C = Immigration
- D = Emigration