**Core Concept**
The question tests the understanding of **embolism** and **arteriovenous communications**. An arteriovenous communication, also known as an arteriovenous fistula or shunt, is an abnormal connection between an artery and a vein.

**Why the Correct Answer is Right**
Although the specific correct answer choice is not provided, the concept being tested involves the passage of an embolus through such a communication. Normally, an embolus would be filtered out by the lungs if it enters the pulmonary circulation. However, if it passes through an arteriovenous communication, it can bypass the lungs and enter the systemic circulation directly.

**Why Each Wrong Option is Incorrect**
**Option A:** This choice is incorrect because it is not specified, and without the correct answer provided, we cannot determine its accuracy.
**Option B:** Similarly, without the specific details of option B, we cannot assess its validity.
**Option C:** This option is also unspecified, making it impossible to evaluate its correctness.
**Option D:** Like the other options, option D's accuracy cannot be determined without more information.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that **paradoxical embolism** occurs when an embolus passes through an arteriovenous communication or a patent foramen ovale, allowing it to bypass the pulmonary circulation and enter the systemic circulation, potentially leading to systemic embolization.

**Correct Answer:** Correct Answer: D. Paradoxical embolus.