Which of the following factors affect human health ?
(i) Infections
(ii) Silent mutations
(iii) Life style
(iv) Genetic disorders

Options

A. (i)m (ii) and (iv)
B. (i) and (ii)
C. (i), (iii) and (iv)
D. (i), (ii), (iii) and (iv)

Explanation

To determine which factors affect human health from the given options, we can analyze each one step by step.

### Step-by-Step Solution:

1. **Infections**:
- Infections are caused by microorganisms such as bacteria, viruses, fungi, or protozoa. These pathogens can lead to various diseases that significantly impact human health. Therefore, infections are a factor that affects human health.

2. **Silent Mutations**:
- Silent mutations are changes in the DNA sequence that do not alter the amino acid sequence of a protein. Since they do not lead to any functional changes in proteins, silent mutations generally do not affect human health. Thus, this factor does not significantly impact health.

3. **Lifestyle**:
- Lifestyle choices, including diet, exercise, sleep patterns, and stress management, play a crucial role in determining health. Poor lifestyle choices can lead to various health issues such as obesity, diabetes, and cardiovascular diseases. Therefore, lifestyle is a significant factor affecting human health.

4. **Genetic Disorders**:
- Genetic disorders arise from inherited traits or mutations in genes passed from parents to offspring. Conditions such as hemophilia and night blindness are examples of genetic disorders that can affect health. Hence, genetic disorders are indeed a factor that affects human health.

### Conclusion:
From the analysis:
- **Factors that affect human health**:
- (i) Infections
- (iii) Lifestyle
- (iv) Genetic disorders
- **Factor that does not affect human health**:
- (ii) Silent mutations

Thus, the correct answer is that infections, lifestyle, and genetic disorders affect human health.