Answer:
b. some other gold diggers had rigged the sled to get stuck.
Step-by-step explanation:
In "The Call of the Wild" by Jack London. the option that is NOT a reason that the dogs couldn't get Hal, Mercedes, and Charles' sled in motion initially is some other gold diggers had rigged the sled to get stuck. Buck has no confidence in Hal and Charles. Buck knows that there are too many items on the sled and they are not tightly packed. The dogs need rest, but they call them lazy. They fail to feed the dogs correctly. All the dogs are wretched, some of the dogs are not as strong as the others. These are the reasons why the dogs fail to put the sled in motion initially.