Three workers working together need 1 hour to construct a wall. The first worker, working alone, can construct the wall twice as fast at the third worker, and can complete the task an hour sooner than the second worker. Then, the average time in hours taken by the three workers, when working along, to construct the wall is

A

$$(\sqrt{33} + 4)/3$$

B

$$(\sqrt{33} + 5)/3$$

C

$$(\sqrt{33} + 6)/3$$

D

$$(\sqrt{33} + 7)/3$$