The height upto which water will rise in a capillary tube will be 

The height of a capillary rise,

$\mathrm{h}=\frac{2\mathrm{Tcos\theta } }{\mathrm{r\rho g}}$

For water, the density is maximum at 4^o C, so height is minimum at 4^o C.

Hence the correct answer is minimum when water temperature is 4°C .