@evan Clearly the answer is going to be different for different people.
Are you rich enough to make a difference with donations? If you are that rich, are you competent / streetwise enough to get your money to a place that matters? (The implosion of the "effective altruism" scene has convinced me almost no one is capable of effective donations.)
I voted activist because it seems like the biggest potential impact for any one person. The others tend to be a matter of numbers.