A collision of two objects occurs in an inertial frame of reference $A$. It is also observed by an observer in another inertial frame of reference $B$ moving uniformly with respect to the frame $A$ along the $z$-axis. Which one of the following is correct?

Assertion: For the object moving on the earth, earth is non-inertial frame of reference.

Reason: Newton's first law of motion does not hold good for the earth.

The normal reaction on a body placed in a lift moving up with a constant acceleration of $2 \mathrm{m} {\mathrm{s}}^{-2}$ is $120 \mathrm{N}$. Mass of the body is:

(Take $g=10\mathrm{ }\mathrm{m} {\mathrm{s}}^{-2}$)

Assertion: In the inertial frame centrifugal force can’t appear.

Reason: In the uniform, circular motion centripetal force will counterbalance the centrifugal force.