Which of the following is correct?

Choose the correct statements.
$A$. Weight of a substance is the amount of matter present in it.
$B$. Mass is the force exerted by gravity on an object.
$C$. Volume is the amount of space occupied by a substance.
$D$. Temperatures below $0^{\circ} C$ are possible in Celsius scale,but in Kelvin scale negative temperature is not possible.
$E$. Precision refers to the closeness of various measurements for the same quantity.

$A$ sample was weighed using two different balances. The results were $(I)$ $3.929 \ g$ and $(II)$ $4.0 \ g$. How would the weight of the sample be reported in $g$?

$2 \times 10^{8}$ atoms of carbon are arranged side by side. Calculate the radius of a carbon atom if the length of this arrangement is $2.4 \, cm$.

What do you mean by significant figures?

Define significant figures.