A truck started from a warehouse, W, and traveled to six depots − depot A through depot F − and stopped exactly once at each depot, in the sequence A − B − C − D − E − F, after which it returned to the warehouse. As the truck traveled across the depots, six different cartons were loaded onto the truck at different depots and unloaded from it at different depots. The weights of the six cartons were 2 tons, 2 tons, 3 tons, 4 tons, 7 tons and 7 tons. Further, the truck was empty when it arrived at depot A and was empty when it left depot F. It is also known that:

(i) At no point of time were two cartons of the same weight present in the truck.

(ii) The total weight of all the cartons in the truck at any given time did not exceed 9 tons.

(iii) Exactly one carton was unloaded at each depot, except at the first and the last depots.

(iv) The 4-ton carton was unloaded at the third depot after the depot at which it was loaded.

(v) Except for the two 2-ton cartons and the 4-ton carton, every other carton was unloaded at the next depot after the respective depot at which it was loaded.

(vi) A total of 5 tons was loaded on to the truck at depot C, while D and F were the only depots where no carton was loaded onto the truck.