c
(c)

\(v=\alpha \sqrt{x}\)

Squaring both sides \(v^2=\alpha^2 x\)

Comparing above equation with \(3^{\text {rd }}\) equation of kinematics.

\(v^2=u^2+2 a x\)

\(\alpha^2 x =2 a x\)

\(\Rightarrow a=\frac{\alpha^2}{2}\)

\(\,\downarrow\)

\(\text { Constant } \rightarrow \text { not a function of time }\)

so,