Final answer:
Chimamanda Ngozi Adichie's speech tone is encouraging, focusing on inspiring the audience towards feminism and gender equality through personal narratives.
Step-by-step explanation:
The tone of Chimamanda Ngozi Adichie’s speech is best described as encouraging. In her speech, Adichie offers an uplifting message that inspires listeners to embrace the concept of feminism and to acknowledge the importance of promoting gender equality. She uses her personal experiences and observations to argue why we should all be feminists, and her approach is one of inclusivity and empowerment rather than confrontation.