A block of mass $\sqrt{2} \mathrm{~kg}$ is placed on a rough horizontal surface. A force ' $F$ ' acting upwards at an angle of $45^{\circ}$ with the horizontal causes the block to start motion. If the coefficient of static friction between the surface and the block is 0.25, the magnitude of the force ' $F$ ' is (Acceleration due to gravity $=10 \mathrm{~ms}^{-2}$ )

• A

  0.5 N
• B

  2 N
• Correct answer
  C

  4 N
• D

  8 N

Hence, the correct answer is option: 'C'.