'Embroil' means to draw someone into a conflict, dispute, or difficult situation - to entangle or implicate in hostilities. Option A (to get involved in hostilities) accurately captures this meaning of becoming entangled in conflict. Option B (arouse bitter feelings) focuses only on emotional aspect, missing the action element. Option C (weaken) means to make weaker - not about conflict involvement. Option D (include) is too neutral - embroil specifically involves conflict/difficulty, not general inclusion.