There are three taps of diameter 2 cm, 3 cm and 4 cm, respectively. The ratio of the water flowing through them is equal to the ratio of the square of their diameters. The biggest tap can fill an empty tank alone in 81 min. If all the taps are opened simultaneously, then how long will the tank take (in min) to be filled?

A

$$34\frac{20}{29}$$

B

$$64\frac{20}{29}$$

C

$$54\frac{20}{29}$$

D

$$44\frac{20}{29}$$