**Core Concept**
The question is testing the understanding of the mechanism of abortion, specifically in the context of a criminal abortion stick. A criminal abortion stick is an instrument used to induce abortion, often in unsafe and unhygienic conditions. The mechanism of abortion in this context is crucial for understanding the risks and complications associated with such practices.

**Why the Correct Answer is Right**
The abortion stick is typically used to cause uterine perforation or to insert foreign objects into the uterus, leading to infection and subsequent abortion. This method of abortion is often associated with severe complications, including hemorrhage, sepsis, and infertility. The mechanism involves the insertion of a foreign object into the uterus, leading to inflammation, infection, and ultimately, abortion.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it doesn't accurately describe the mechanism of abortion caused by a criminal abortion stick. The stick doesn't cause a decrease in progesterone levels, which is a more common mechanism of medical abortion.
**Option B:** This option is incorrect because it's too vague and doesn't specifically describe the mechanism of abortion caused by a criminal abortion stick. While prostaglandins can cause uterine contractions, it's not the primary mechanism in this context.
**Option C:** This option is incorrect because it's not a recognized mechanism of abortion caused by a criminal abortion stick. The stick doesn't cause an increase in prostaglandins, which is a more common mechanism of medical abortion.

**Clinical Pearl / High-Yield Fact**
It's essential to recognize the risks associated with criminal abortion practices, including uterine perforation, infection, and infertility. Healthcare providers should be aware of these risks and provide safe and effective alternatives to abortion, such as medical or surgical abortion services.

**Correct Answer:** C.