c
Let \(V_1\) and \(V_2\) are velocity just before and just after hitting the floor.

\(\frac{V_1}{V_2}=4 \Rightarrow V_1=4 V_2\)

\(K E_{\text {bygove }}=\frac{1}{2} m V_1^2\)

\(K E_{\text {affor }}=\frac{1}{2} m V_2^2=\frac{1}{2} \frac{m \cdot V_1^2}{16}\)

\(\Delta K E=\frac{1}{2} m V_1^2\left(\frac{1}{16}-1\right)=\frac{-15}{32} m V_1^2\)

\(\% \text { change }=\frac{\Delta K E}{K E_{\text {before }}} \times 100 \%\)

\(=\frac{-15}{16} \times 100=\frac{-375}{4} \%\)