(c) Water will not leak out from the hole if the weight of water in the water column is supported by the force due to surface tension.
Using the relation,
$h = \frac{2T}{r\rho g}$
$= \frac{2 \times 7.5 \times 10^{- 2}}{0.5 \times 10^{- 3} \times 10^{3} \times 10}$
$= 3 \times 10^{- 2}\ m = 3\ cm$