Let's break this one down.
While this is a true statement, it has nothing to do with the dissociation curve. There are many things that will shift the curve left, not just HgF, so to me, this answer assumed too much.
If they had asked something about Hgb electrophoresis, or the timing of when the thalassmias present, then this answer might make sense.
HgF's increased affinity for O2 (not really increased, just less susceptible to the effect of BPG than HgA,) would make it easier to transfer O2 to the fetus. This one made the most sense to me, I chose this one. Even then, a better answer would be "There is a driving force for oxygen to be transferred from the mom to the fetus"
This one depends on what "tissue" you're talking about. Mom->Fetus across placenta? Sure. Fetal blood->fetal tissues? No. Any left-shift of the curve makes it harder to drop off O2. That's why high altitude increases your BPG concentration.
Greater O2 sat? Greater O2 demand? Greater O2 delivery? The incompleteness of the answer left much to be
Oh, and didn't I tell you? We never covered this in class! Yes, the faculty will remove questions, but that would mean ~30% of this exam would go.