text: The<unk>  is the<unk>  side of the breastbone.
option_0: Left sternal border
option_1: Left margin of heart
option_2: Right border of heart
option_3: Sternocostal surface
option_4: Sternal plane
option_5: Midclavicular line
option_6: Horizontal fissure of right lung
option_7: Floating rib