Identify the incorrect statement regarding the action of RU- 486

Options

A. Blocks the action of progesterone essential for implantation of embryo
B. It is antagonistic to estrogen
C. Leads to death of embryo followed by spontaneous abortion
D. Inhibit the release of hCG from placenta

Answer

**Step-by-Step Solution:**

1. **Understanding RU-486**: RU-486, also known as mifepristone, is a medication used to induce abortion. It works by blocking the hormone progesterone, which is essential for maintaining pregnancy.

2. **Analyzing the Statements**: The question asks to identify the incorrect statement regarding the action of RU-486. We will evaluate each statement provided in the options.

3. **Evaluating Statement 1**: The first statement claims that RU-486 blocks the action of progesterone, which is essential for the implantation of the embryo. This statement is **correct** because progesterone is crucial for maintaining the uterine lining for implantation.

4. **Evaluating Statement 2**: The second statement claims that RU-486 is antagonistic to estrogen. This statement is **incorrect** because RU-486 does not antagonize estrogen; instead, it can increase estrogen production, which can prevent implantation or embryo growth.

5. **Conclusion**: Based on the evaluations, the incorrect statement regarding the action of RU-486 is the second option, which states that RU-486 is antagonistic to estrogen.

**Final Answer**: The incorrect statement regarding the action of RU-486 is the second option: "RU-486 is antagonistic to estrogen."

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