Final answer:
Third-wave feminism's key contribution is the acknowledgment that gender cannot be considered separately from other social categories and that feminism should allow for individual self-definition. Option A.
Step-by-step explanation:
One of the most significant contributions of third-wave feminism is its understanding that gender cannot be considered in isolation.
This wave of feminism has emphasized the concept of intersectionality, recognizing that gender intersects with race, class, ethnicity, sexuality, and other social categories, affecting the experiences and oppressions faced by individuals.
Third-wave feminists argue for a personalized understanding of feminism, where each individual defines gender justice for themselves, challenging the notion of a universal feminist ideal. So Option A is correct.