$$\text{The position vector of a moving body at any instant of time is given as }\vec r=(5t^2\hat i-5t\hat j)\,m.\text{The magnitude and direction of velocity at } t=2\,s \text{ is:}$$

A

$$ 5\sqrt{15}\,\text{m/s, making an angle of } \tan^{-1}4 \text{ with -ve } Y\text{-axis} $$

B

$$ 5\sqrt{15}\,\text{m/s, making an angle of } \tan^{-1}4 \text{ with +ve } X\text{-axis} $$

C

$$ 5\sqrt{17}\,\text{m/s, making an angle of } \tan^{-1}4 \text{ with +ve } X\text{-axis} $$

D

$$ 5\sqrt{17}\,\text{m/s, making an angle of } \tan^{-1}4 \text{ with -ve } Y\text{-axis} $$