I would have to say probably d.
When a skeletal muscle relaxes,myosin head attach to actin by breaking down ATP to ADP and phosphate with the help of myosin ATPase. The myosin head forms the cross -bridges on the active site of the actin.The cross-bridge pulls the actin which slide over the myosin. The release of ADP completes the cross-bridge movements . ATP attaches to myosin, and break the actin -myosin cross-bridge. Thus breaking of ATP into ADP and phosphate help the thin filament to return to their original position.
The is should be C, Im not 100% sure though...
C.All living things are made of the same elements
The chamber is the left atrium.
The lungs help exchange the deoxygenated blood which are full of wast materials into oxygenated and blood full of nutrients. These oxygenated blood are then transported through the pulmonary vein, the only vein in the body which transports oxygenated blood. These blood are then transported back into the heart, which is the left atrium specifically.
Those blood is then pushed down to the left ventricle, and then pumped to the whole body (except lungs), in order to keep the body functioning by providing oxygen and nutrients for cellular respiration.
Meanwhile, the deoxygenated blood are received by the right atrium, and is then transported back to the lungs for exchange again, through the right ventricle and pulmonary artery.
