Water rises to a height of 10 cm in a certain capillary tube. An another identical tube when dipped in mercury the level of mercury is depressed by 3.42 cm. Density of mercury is 13.6 g/cc. The angle of contact for water i contact with glass is 0° and mercury in contact with glass is 135°. The ratio of surface tension of water to that of Hg is
(a) 1 : 3
(b) 1 : 4
(c) 1 : 5.5
(d) 1 : 6.5
