It is an oversimplified view of cattle raising to say that all one has to do with cattle is leave them alone while they feed themselves, corral them, and to drive them to market when the time is ripe.
(A) all one has to do with cattle is leave them alone while they feed themselves, corral them, and to
PROBLEM: the "to" at the end isn't parallel with "leave" or "corral".
(B) all one has to do with cattle is to leave them alone to feed themselves, to corral them, and
PROBLEM: We need our last "to".
(C) all one has to do with cattle is leave them alone while they feed themselves and then corral them and
ANSWER: Okay. So this one can technically work. Basically, we have two lists, and one of those lists has a list of two things INSIDE it. That's why we end up with two "and" in a row (ANOTHER EXAMPLE: I like reubens and peanut butter and jelly sandwiches). But there's a problem, in that
(D) the only thing that has to be done with cattle is leave them alone while they feed themselves, corral them, and
PROBLEM/POSSIBLE ANSWER: Okay. As I said, I much prefer "one" on BOTH of these questions, because it creates an actor/subject for the verbs. But the list here is problematic, because corral has two meanings. It can mean "round up" (which makes the last sentence make sense, because you would corral them and bring them to market one after the other). However, it can also mean "keep in a corral", which you would ALSO have to do in order to keep cattle, meaning that THIS list would ALSO be correct. While the previous sentence would still make more sense, I don't see a grammatical issue with the list here.
(E) the only thing that has to be done with cattle is to leave them alone while they feed themselves, to corral them, and
PROBLEM: We lost our last "to" again.
-t