This sentence is a fragment
I would go for doing a burst of physical activities, as when you do these, endorphins are released, and you can focus better afterward.
The correct answer is B. Contrite.
Contrite means a feeling or expressing penitence or remorse. Someone that is affected by guilt. So the complete sentence should be:
The foster mother of Anne of Green Gables offers her a contrite apology after unjustly punishing her for the missing brooch.