For This Year's Mayoral Election, Voter Dissatisfaction Is Very High

Multiple Choice

For this year's mayoral election, voter dissatisfaction is very high. In a survey of 500 likely voters, 210 said they planned to write in an independent candidate rather than vote for the Democrat or Republican candidate for mayor.
What is the probability that a surveyed voter plans to write in an independent candidate?

A) 0.42
B) 0.58
C) 0.5
D) 0.21