<span>c.
Birds following grazing animals who stir up insects
Is correct</span>
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
Weather : too cold or too hot due to climate change
Habitat can be destroyed due to natural phenomenon
Prey cut off by physical barrier
Lack of water