Answer:
C : A city passing a law to ban discrimination
Step-by-step explanation:
The definition of Social Policy is, : Social policy is a plan or action of government or institutional agencies which aim to improve or reform society. - Wiki
Reforming society by taking away discrimination would make a huge positive impact compared to the rest of the answers there for the answer must be based off of making a plan/ action to stop discrimination through a law must be the answer so that's why I chose C.