**Core Concept**
The ideal cholesterol level is a crucial factor in assessing cardiovascular risk and guiding lipid-lowering therapy. Cholesterol levels are classified into different categories based on their risk profile, with higher levels indicating a greater risk of cardiovascular disease.

**Why the Correct Answer is Right**
The correct answer is 200 mg/dL, which is below the high-risk threshold for LDL (low-density lipoprotein) cholesterol. The American College of Cardiology and the American Heart Association (ACC/AHA) guidelines recommend treating patients with LDL cholesterol levels ≥190 mg/dL with statins, regardless of their 10-year cardiovascular risk. Levels between 160-189 mg/dL may also warrant treatment, depending on individual risk factors. Therefore, an LDL cholesterol level of 200 mg/dL or higher is considered high-risk, and levels below 200 mg/dL are generally considered desirable.

**Why Each Wrong Option is Incorrect**
**Option A:** 300 mg/dL is actually the upper limit of the high-risk category for LDL cholesterol, as it indicates a very high risk of cardiovascular disease. Levels above this threshold are often associated with a significant increase in cardiovascular events.
**Option B:** 220 mg/dL is above the desirable level for LDL cholesterol and may be considered high-risk, depending on individual risk factors. However, it is not as high-risk as levels above 220 mg/dL.
**Option D:** 350 mg/dL is an extremely high level of LDL cholesterol, indicating a very high risk of cardiovascular disease. This level is often associated with severe atherosclerotic disease and a high risk of cardiovascular events.

**Clinical Pearl / High-Yield Fact**
The ACC/AHA guidelines recommend calculating the 10-year cardiovascular risk using the Pooled Cohort Equations (PCE) to guide lipid-lowering therapy. The PCE takes into account various risk factors, including age, sex, cholesterol levels, blood pressure, and smoking status, to estimate the 10-year risk of cardiovascular events.

**✓ Correct Answer: C. 200. LDL cholesterol levels below 200 mg/dL are generally considered desirable and indicate a lower risk of cardiovascular disease.**