The lateral thoracic wall protects the lungs, heart, great vessels and some abdominal organs. Therefore, it includes the ribs, as its main function is to protect those structures, so b) is incorrect. The diaphragm too is located in this area, so a) is also wrong, and the intercostal muscles as wellm which means that c) is incorrect as well. The parietal pleura revests the lungs and the internal thoracic wall, so it is also a part of the thoracic wall, but the visceral pleura revests only the lungs. So, d) is also wrong and the correct answer is e) visceral pleura.