Final answer:
B. Assertiveness is the term that describes speaking up for oneself respectfully without infringing on others' rights, distinguishing it from aggressiveness, passiveness, and companionship.
Step-by-step explanation:
The term that means speaking up for oneself without violating the rights of others is B. assertiveness. Assertiveness involves expressing one's opinions and needs directly and respectfully, without aggression or passivity. On the other hand, aggressiveness can involve violating others' rights, passiveness usually means not speaking up for oneself, and companionship is more about sharing a bond with someone else and is not directly related to self-advocacy.