Three metal walls of the same cross-sectional area having thermal conductivities in the ratio 1:2:4 transfers heat at the rate of 3000 kJ/hr. For the same wall thickness, the
temperature drops will be in the ratio

A

$$1 : 2 : 4$$

B

$$1 : \frac{1}{2} : \frac{1}{4}$$

C

$$\frac{1}{4} : \frac{1}{2} : 1$$

D

$$1 : 1 : 1$$