Property of contact inhibition is seen in:

Options

A. Normal cells
B. Benign tumours
C. Malignant tumours
D. More than one option is correct

Answer

### Step-by-Step Solution:

1. **Understanding Contact Inhibition**:
- Contact inhibition is a regulatory mechanism that stops cells from dividing when they come into contact with each other. This is a crucial property of normal cells that helps maintain tissue architecture and prevents uncontrolled cell growth.

2. **Analyzing the Options**:
- **Option A: Normal Cells**: Normal cells exhibit contact inhibition. When they come into contact with each other, they stop dividing, which prevents overcrowding and maintains proper tissue structure.
- **Option B: Benign Tumors**: Benign tumors may exhibit some degree of contact inhibition, but they can still grow larger than normal cells. However, they do not invade surrounding tissues like malignant tumors.
- **Option C: Malignant Tumors**: Malignant tumors do not exhibit contact inhibition. These cancerous cells continue to grow and divide uncontrollably, leading to tumor formation and potential invasion of surrounding tissues.
- **Option D: More than one option is correct**: This option suggests that multiple options could be correct, but based on the analysis, only normal cells exhibit true contact inhibition.

3. **Conclusion**:
- Based on the properties of the different cell types, the correct answer is **Option A: Normal Cells**. They are the ones that exhibit contact inhibition effectively.

### Final Answer:
The property of contact inhibition is seen in **normal cells** (Option A).