Statement-I : If two particles, moving with constant velocities are to meet, the relative velocity must be along the line joining the two particles.
Statement-II : Relative velocity means motion of one particle as viewed from the other.

Options

A. Statement-I is true, Statement-II is true, Statement-II is correct explanation for Statement-I
B. Statement-I is true, Statement-II is true, Statement-II is NOT a 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 question, we need to analyze both statements and determine their validity and relationship.

### Step 1: Analyze Statement I
**Statement I:** "If two particles, moving with constant velocities are to meet, the relative velocity must be along the line joining the two particles."

- Let's denote the two particles as A and B, with velocities \( \vec{V_A} \) and \( \vec{V_B} \) respectively.
- For the two particles to meet, they must be moving towards each other, meaning that the vector representing their relative velocity \( \vec{V_{AB}} = \vec{V_A} - \vec{V_B} \) should point along the line joining them.
- If the relative velocity is not directed along the line joining them, they will not meet, as they will be moving apart or parallel without converging.
- Thus, **Statement I is true**.

### Step 2: Analyze Statement II
**Statement II:** "Relative velocity means motion of one particle as viewed from the other."

- Relative velocity is defined as the velocity of one object as observed from another object. It is indeed the motion of one particle with respect to another.
- This definition aligns with the concept of relative motion in physics.
- Therefore, **Statement II is also true**.

### Step 3: Determine the Relationship
- Now, we need to determine if Statement II provides a correct explanation for Statement I.
- Statement II defines relative velocity, but it does not explain why the relative velocity must be along the line joining the two particles for them to meet.
- Thus, while both statements are true, Statement II does not serve as an explanation for Statement I.

### Conclusion
Both statements are true, but Statement II is not the correct explanation for Statement I.

**Final Answer:** Both statements are true, but Statement II is not the correct explanation for Statement I.

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