## Core Concept
Libman-Sacks endocarditis is a form of non-bacterial endocarditis seen primarily in patients with systemic lupus erythematosus (SLE). It is characterized by the presence of sterile vegetations on heart valves. These vegetations are composed of immune complexes, platelets, and fibrin.

## Why the Correct Answer is Right
The correct answer, **C. Verrucous and less likely to embolize**, is right because Libman-Sacks endocarditis is known for causing verrucous vegetations. These vegetations are typically smaller, more friable, and less likely to embolize compared to the vegetations seen in infective endocarditis. The vegetations in Libman-Sacks endocarditis are usually found on either side of the valve leaflets and can be associated with SLE and antiphospholipid syndrome.

## Why Each Wrong Option is Incorrect
- **Option A: Large and friable** - This is incorrect because while the vegetations can be friable, they are not typically described as large in Libman-Sacks endocarditis.
- **Option B: Usually on the left side** - Although Libman-Sacks vegetations can occur on either side of the heart, they are not exclusively or usually limited to the left side, making this statement not specifically characteristic.
- **Option D: Highly likely to cause embolism** - This is incorrect because one of the distinguishing features of Libman-Sacks endocarditis is that the vegetations are less likely to embolize compared to those in bacterial endocarditis.

## Clinical Pearl / High-Yield Fact
A key point to remember is that Libman-Sacks endocarditis is associated with systemic lupus erythematosus and antiphospholipid syndrome. The vegetations are sterile, making this condition distinct from infective endocarditis.

## Correct Answer: C. Verrucous and less likely to embolize