An oil ring bearing of transmission shaft of 50mm diameter in which journal rotates at 1450 rpm, radial clearance and bearing pressure are 20 micron and 4N/mm2. If Somerfield number is 0.0637, the viscosity of lubricant is
(a) 5.75 cp (b) 6.75 cp
(c) 15.75 cp (d) 16.75 cp