题目选项分析

Advertisement: When your car's engine is running at its normal operating temperature, any major brand of motor oil will protect it about as well as Tuff does. When the engine is cold, it is a different story: Tuff motor oil flows better at lower temperatures than its major competitors do. So, if you want your car's engine to have maximum protection, you should use Tuff.

which of the following, if true, most strengthens the argument in the advertisement?

【选项】Tuff motor oil is periodically supplied free of charge to automobile manufacturers to use in factory-new cars.