Question

Breast cancer researchers found that, out of a sample of 1000 women who had been treated for breast cancer, over 60% had had a miscarriage in their lifetime. This led the researchers to conclude that there is a connection between breast cancer and miscarriages, and to encourage all women who have had miscarriages to be screened for breast cancer more frequently than women who have not had miscarriages. Which of the following, if true, most weakens the researchers' conclusions?

• A. Women who have had miscarriages are also often taking birth control pills, which have a known connection to breast cancer.
• B. Women who have not had breast cancer also have a high rate of miscarriage after age 35.
• C. Women who have had previous miscarriages sometimes use fertility treatments that are thought to have connections with uterine cancer.
• D. In the general population, roughly 6 out of 10 women will have a miscarriage at some point in their lifetime.
• E. Most of the women in the study had also at least one living child.

Hint:

Always consider alternative explanations for a correlation presented in an argument. In this case, birth control pills provide a plausible alternative explanation.

Answer 1

The Correct Option is A

Step 1: Understanding the argument.
The researchers conclude that there is a connection between breast cancer and miscarriages based on the fact that many women who had breast cancer also had miscarriages. To weaken this conclusion, we need to find an alternative explanation for the relationship.

Step 2: Analysis of options.
- (A) Women who have had miscarriages are also often taking birth control pills, which have a known connection to breast cancer: Correct. This option provides an alternative explanation that could explain the correlation, weakening the conclusion that miscarriages cause breast cancer.
- (B) Women who have not had breast cancer also have a high rate of miscarriage after age 35: Incorrect. This does not weaken the connection, but rather shows that miscarriage is common among women of a certain age group.
- (C) Women who have had previous miscarriages sometimes use fertility treatments that are thought to have connections with uterine cancer: Incorrect. While this is relevant to uterine cancer, it does not weaken the argument about breast cancer.
- (D) In the general population, roughly 6 out of 10 women will have a miscarriage at some point in their lifetime: Incorrect. This statistic does not address the connection between breast cancer and miscarriage specifically.
- (E) Most of the women in the study had also at least one living child: Incorrect. This fact does not weaken the claim about the relationship between miscarriage and breast cancer.

Step 3: Conclusion.
The correct answer is (A) Women who have had miscarriages are also often taking birth control pills, which have a known connection to breast cancer.

Final Answer: \[ \boxed{(A) \, \text{Women who have had miscarriages are also often taking birth control pills, which have a known connection to breast cancer.}} \]