Lydia writes the equation below with a missing value. She puts a value in the box and says that the equation represents a direct variation. Which explains whether the equation could represent a direct variation? A. If she puts 0 in the box she would have a direct variation. B. If she puts 5 in the box she would have a direct variation. C. The equation is not of the form , so it cannot represent a direct variation. D. The equation has a minus sign, so it cannot represent a direct variation.