An object of mass $2 \, kg$ is placed at rest in a frame $S_1$ moving with velocity $10 \hat{i} + 5 \hat{j} \, m/s$ and having acceleration $5 \hat{i} + 10 \hat{j} \, m/s^2$. The object is also seen by an observer standing in a frame $S_2$ moving with velocity $5 \hat{i} + 10 \hat{j} \, m/s$. Calculate the pseudo force acting on the object. Which frame is responsible for this force?

• A
  $F = -10 \hat{i} - 30 \hat{j}$ due to acceleration of frame $S_1$
• B
  $F = -10 \hat{i} - 20 \hat{j}$ due to acceleration of frame $S_1$
• C
  $F = -20 \hat{i} - 20 \hat{j}$ due to acceleration of frame $S_1$
• D
  none of these