1) Construct a valid rebuttal using at least one threat to validity to: (B) The greater the cost of an alternative, the less likely it is that the alternative will be pursued.

2) Construct a valid rebuttal using at least one threat to validity to: (W) The enforcement of the maximum speed limit of 55 mph increases the costs of exceeding the speed limit.

3) Construct a valid rebuttal using at least one threat to validity to: (I) The mileage death rate fell from 4.3 to 3.6 deaths per 100 million miles after the implementation of the 55-mph speed limit.