Conclusion: Precision is not important for users
a) Around the time the new razor was unveiled, a consumer guide reported that many shoddy haircuts and shaves were the result of faulty precision features in razors.
This statement does not challenge the the conclusion or the assumption on which the conclusion stands i.e. high precision electric razors sell poorly as compared to older counterparts. Hence incorrect
b)Razor users typically find that they get the best results from older razors because
...
a) Around the time the new razor was unveiled, a consumer guide reported that many shoddy haircuts and shaves were the result of faulty precision features in razors.
This statement does not challenge the the conclusion or the assumption on which the conclusion stands i.e. high precision electric razors sell poorly as compared to older counterparts. Hence incorrect
b)Razor users typically find that they get the best results from older razors because
...