**Core Concept**
The question is testing the knowledge of risk reduction strategies for ovarian cancer in women with BRCA-1 and BRCA-2 mutations. This involves understanding the genetic basis of ovarian cancer and the role of BRCA genes in tumor suppression.

**Why the Correct Answer is Right**
Women with BRCA-1 and BRCA-2 mutations have a significantly increased risk of developing ovarian cancer. Prophylactic salpingo-oophorectomy (removal of the ovaries and fallopian tubes) is a recommended strategy to reduce this risk. This is because the BRCA genes are primarily expressed in the ovaries and fallopian tubes, and removing these tissues can significantly reduce the risk of ovarian cancer. Studies have shown that prophylactic salpingo-oophorectomy can reduce the risk of ovarian cancer by up to 80-90% in women with BRCA mutations.

**Why Each Wrong Option is Incorrect**
**Option A:** Chemoprevention with tamoxifen or raloxifene is not recommended for ovarian cancer prevention in women with BRCA mutations. While these medications have been shown to reduce the risk of breast cancer in high-risk women, their effectiveness in reducing ovarian cancer risk is not established.

**Option B:** Screening with CA-125 or transvaginal ultrasound is not a recommended strategy for reducing the risk of ovarian cancer in women with BRCA mutations. While these tests can help detect ovarian cancer at an early stage, they are not effective in preventing the disease.

**Option C:** Lifestyle modifications such as a healthy diet and regular exercise may help reduce the risk of ovarian cancer, but they are not sufficient to reduce the risk in women with BRCA mutations. These women require more aggressive risk-reduction strategies.

**Clinical Pearl / High-Yield Fact**
Women with BRCA mutations should be counseled about the risks and benefits of prophylactic salpingo-oophorectomy and encouraged to make an informed decision about their risk-reduction strategy. This decision should be made in consultation with a gynecologic oncologist or a genetic counselor.

**Correct Answer:** C. Prophylactic salpingo-oophorectomy.