The features of cretinism inciudes -

Options

A. mental retardation, low, I.Q.
B. Abnormal skin, stunted growth
C. Deaf-mutism
D. All

Answer

### Step-by-Step Solution:

1. **Understanding Cretinism**: Cretinism is a condition that arises due to severe hypothyroidism, particularly during pregnancy. It is characterized by a deficiency of the thyroid hormone thyroxin.

2. **Effects of Thyroxin Deficiency**: Thyroxin is crucial for normal physical and mental development. A lack of this hormone during fetal development can lead to significant impairments.

3. **Physical Growth Impairment**: Children born with cretinism often exhibit stunted physical growth. This means they may be shorter and have underdeveloped body structures compared to their peers.

4. **Mental Development Issues**: Cretinism also leads to mental deterioration. Affected individuals may have a lower IQ, which indicates impaired cognitive function and learning abilities.

5. **Additional Features**: Other features of cretinism can include:
- Abnormal skin conditions.
- Deafness or mutism, indicating that the child may have difficulties with hearing and speaking.

6. **Summary of Features**: Therefore, the features of cretinism include:
- Stunted physical growth.
- Low IQ and mental deterioration.
- Abnormal skin conditions.
- Deafness and mutism.