Concept:The subject is “one,” which is singular, and “stray” is an action the ball does itself, not something done to it.Explanation:“One of the balls” takes a singular verb, so we use “has,” not “have.”“Strayed” here is active voice, meaning the ball moved away by itself.The passive form “been strayed” is incorrect because “stray” is not normally used passively.Therefore, the correct choice is “has strayed.”Answer:D. has strayed