Statement I: A body in equilibrium has to be at reat only.
Statement II: A body in equilibrium may be moving with a constant speed along a straight line path.

Options

A. Statement I is true, statement II is true, Statement II is the correct explanation for statement I.
B. Statemet I is true, Statement II is true , Statement II is NOT the correct explanation for Statement I
C. Statement I is True, Statement II is False.
D. Statement I is False, Statement II is true

Explanation

To solve the problem, we need to analyze both statements regarding the concept of equilibrium in physics.

### Step 1: Understand the concept of equilibrium
Equilibrium in physics refers to a state where the net force acting on a body is zero. This means that the body is either at rest or moving with a constant velocity (which includes moving in a straight line at constant speed).

### Step 2: Analyze Statement I
**Statement I:** "A body in equilibrium has to be at rest only."
- This statement is **incorrect**. A body can be in equilibrium and still be in motion. If the body is moving with a constant velocity (constant speed in a straight line), the forces acting on it are balanced, and it is still considered to be in equilibrium.

### Step 3: Analyze Statement II
**Statement II:** "A body in equilibrium may be moving with a constant speed along a straight line path."
- This statement is **correct**. According to Newton's First Law of Motion, an object in motion will remain in motion with the same speed and in the same direction unless acted upon by a net external force. Therefore, if a body is moving at a constant speed in a straight line, the forces acting on it are balanced, indicating that it is in equilibrium.

### Conclusion
- Statement I is incorrect.
- Statement II is correct.

Thus, the final conclusion is:
- Statement I: False
- Statement II: True