Two identical thermometers are constructed with bulbs of volume 0.50cm3 and capillary area 5.0×10−3cm2. One is filled with mercury (real γr=1.8×10−4K−1) and the other with alcohol (real γr=1.1×10−3K−1). The glass in both thermometers has coefficient γg=9.0×10−6K−1. Taking the apparent expansion to be constant, the ratio of their sensitivities (length rise per degree Celsius for alcohol to that for mercury) is closest to
a) 6.1
b) 7.0
c) 6.4
d) 1.0