Oh this is a tough choice, lots of potential all around.
I would lean toward C or D in order to try to fix a difficult situation, perhaps. Maybe if he keeps the kids but left Bonnie, it would parallel his father's situation in a small way, which could be interesting.
One thing I did when a family had a lot of kids but I personally couldn't take it, was have my sim become a sort of absent father. Under the pretense of work, I had him leave for long stretches of time. Off to granite falls or Selvadorada alone for research purposes, and so forth. He'd make an appearance with the family every few sim years, act as if he'd never left. Stay for a while, be great, and then leave when the pressure became too much again. The downside is that this option doesn't give you as much control over what happens with the children since you have potentially less time home to shape them.
Of course, with little money to his name, this could be difficult to pay for, anyway. Unless you're into the idea of him selfishly tapping out the family's finances to go out on his own.
