The answer is that Both aid in the expansion and relaxation of lungs. Diaphragm and the rib muscles are vital in the breathing process. During inhalation the intercostal muscles contract, expanding the ribcage, the diaphragm contracts, pulling downwards to increase the volume of the chest, pressure inside the chest is lowered and air is sucked into the lungs. During exhalation the intercostal muscles relax, the ribcage drops inward and downwards, the diaphragm relaxes, moving back upwards, decreasing the volume of the chest, the pressure inside the chest increases and air is forced out.
B because a new species adds more diversity to your ecosystem
These primates have retained some primitive mammalian anatomical and behavioral traits, such as a strong sense of smell with an associated longer snout, eyes that are positioned more to the sides of the head, a smaller brain, a distinct breeding season and litters of offspring, nocturnal activity and the ability to synthesis vitamin C.