Final answer:
Hajime Isayama has not specified a gender for Hange Zoë in Attack on Titan, leaving it open to audience interpretation.
Step-by-step explanation:
In Attack on Titan, the creator Hajime Isayama has intentionally avoided specifying a particular gender for the character of Hange Zoë. Isayama has mentioned in interviews that they left Hange's gender up to the interpretation of the reader/audience, thus never confirming it within the manga itself or supplementary materials. This approach by Isayama creates a character inclusive to all interpretations, and often prompts discussion within the Attack on Titan fan community.