A cylinder of radius $250$ mm and weight, $W=10$ kN is rolled up an obstacle of height $50$ mm by applying a horizontal force $P$ at its centre as shown in the figure.

All interfaces are assumed frictionless. The minimum value of P is

1. $4.5$ kN
2. $5.0$ kN
3. $6.0$ kN
4. $7.5$ kN