Gravitational deflection reverses rock's velocity direction Steps:

• Rock starts at large distance from star with speed 1.0 × 10³ m/s toward star (initial velocity -1.0 × 10³ m/s, taking arrow R as positive outgoing direction).
• Gravity causes 180° reversal; rock exits at large distance with speed 1.0 × 10³ m/s away (final velocity +1.0 × 10³ m/s).
• Change in velocity Δv = final velocity - initial velocity = 1.0 × 10³ - (-1.0 × 10³) = 2.0 × 10³ m/s.
• The star's mass >> rock's mass, so star's motion negligible; focus on rock (S).

Why B is correct:

• Change in velocity is v_final - v_initial; for opposite directions and equal speeds in hyperbolic orbit, Δv = 2v by vector subtraction.

Why the others are wrong:

• A: Δp of S (star) opposes rock's Δp, but arrow X direction unspecified in problem.
• C: Conservation of momentum requires |Δp_R| = |Δp_S|, not 10 times greater.
• D: Rock's momentum changes due to gravitational force altering its velocity.

Final answer: B