Which statement best describes the role of decomposers in an ecosystem?

a. decomposers restrict the populations of primary consumers.

b. decomposers convert solar energy to chemical energy.

c. decomposers return nutrients to the soil.

d. decomposers form the top of the food web.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.