Which of the following most logically completes the argument below?
North Dakota farmers are currently deciding between planting winter canola this fall or spring canola next spring. Winter canola varieties planted in the fall have always shown a potential for improved yield over spring-planted varieties. The most significant problem with winter canola is its inability to survive winter conditions. Because of a colder than normal winter, per acre yields for winter canola, though not for spring canola, would be much lower than average. Therefore, planting spring canola will be more profitable than planting winter canola, since __________.