Ann wants to choose from two telephone plans. Plan A involves a fixed charge of $10 per month and call charges at $0.10 per minute. Plan B involves a fixed charge of $15 per month and call charges at $0.08 per minute. Which statement correctly compares the two plans? A) Plan A is cheaper than Plan B if the usage is less than 400 minutes. B) Plan A is cheaper than Plan B if the usage is less than 250 minutes. C) Plan A is cheaper than Plan B if the usage is more than 400 minutes. D) Plan A is cheaper than Plan B if the usage is more than 250 minutes.