We're the colonists justified in resisting British policies from 1763 to 1775?

Yes, They were.

Explanation:

British policies from 1763 to 1775 were made to help the British recuperate the large debt that they get from their wars with other European empires. (mostly France Empire).

They created an unfair taxation laws from the colonists in order to cut down their income and distribute it to the British government. This could drive many of the people in the colonists into poverty. This is why I believed that the colonists' resistance were justified.

the answer your looking for is c. : )