A laser beam is used for carrying our surgery because it

Options

A. Is highly monochromatic
B. Is highly coherent
C. Is highly directional
D. Can be sharply focussed.

Explanation

To solve the question, "A laser beam is used for carrying out surgery because it...", we need to analyze the properties of laser beams and their applications in surgical procedures.

### Step-by-Step Solution:

1. **Understanding Laser Properties**:
- Lasers are known for several key properties: they are monochromatic (emitting light of a single wavelength), coherent (the light waves are in phase), and highly directional (the light travels in a narrow beam).

2. **Application in Surgery**:
- In surgical procedures, precision is critical. Surgeons need to target very specific areas without affecting surrounding tissues.

3. **Focusing Ability**:
- The ability of a laser to be sharply focused to a point is essential. This means that the laser can concentrate its energy on a very small area, allowing for minimal damage to adjacent tissues.

4. **Conclusion**:
- Therefore, the main reason a laser beam is used in surgery is that it can be sharply focused to a point, enabling precise cutting or treatment of tissues.

### Final Answer:
A laser beam is used for carrying out surgery because it can be sharply focused to a point.

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