Which condition results in a systolic murmur with an ejection click located at the left upper sternal border (LUSB)?

The condition that typically results in a systolic murmur with an ejection click located at the left upper sternal border (LUSB) is pulmonary stenosis. In pulmonary stenosis, the narrowing of the outflow tract from the right ventricle leads to an increased velocity of blood flow through the pulmonary valve during ventricular systole. This high flow creates a characteristic systolic murmur, which is often described as a "crescendo-decrescendo" quality. Additionally, the ejection click is caused by the abrupt opening of the pulmonary valve, which occurs after the ventricular contraction has begun. The anatomical consideration of the left upper sternal border aligns with the location of the pulmonary valve, making it the most appropriate choice for this clinical presentation.

Other conditions listed do not typically produce this specific combination of murmur and click at the LUSB, which is unique to pulmonary stenosis.