Pulmonary-in these sorts of questions, you need to identify the valve immediately distal to the area of high pressure. this is the valve that must be blocked, because you can assume that blood is backing up into the area where the pressure is high. in this case, pressure is high in the right ventricle. so, there must be stenosis of the pulmonic valve, which allows blood to leave the right ventricle and travel to the lung.
if there was stenosis of the aortic valve, pressure would be high in the left ventricle. if there was stenosis of the tricuspid valve, pressure would be high in the right atrium. if there was stenosis of the mitral valve, pressure would be high in the left atrium. if you understand the path of blood flow in the heart, you can understand all these scenarios!