What is HDL commonly referred to as?

HDL is commonly referred to as "good cholesterol" because it plays a critical role in transporting cholesterol away from the arteries and back to the liver, where it can be processed and removed from the body. High levels of HDL cholesterol are associated with a lower risk of heart disease, as it helps to reduce the buildup of plaque in the arteries, thereby promoting better cardiovascular health. This function contrasts with LDL (low-density lipoprotein), which is often referred to as "bad cholesterol" because it can lead to the accumulation of cholesterol in the arteries, increasing the risk of heart disease.

In summary, HDL's beneficial role in cholesterol metabolism and cardiovascular health is why it is termed as "good cholesterol," making the first option accurate.