Answer:
Step-by-step explanation:Braxton is testing 2 different types of motor oil in his truck to determine which one will last longer.Now, he adds Brand A to the truck and Brand B to his sister's car.Now, as Braxton wants to test the motor oil in his truck so there is no need of adding the motor oil to his sister's car as by doing so he cannot result in to a meaningful conclusion.So, Braxton need to add both the motor oil into his truck one by one.Hence, The conclusion of Braxton is not valid because he added Brand B to his sister's car, not the truck.Therefore, The correct option is A.
Step-by-step explanation: