How is the eye able to see distant and near objects so clearly?
 

Humans are vertebrates and therefore the vertebrate eye can change its optical power to keep up a transparent image of objects at various distances. When the ciliary muscles of the eyes are relaxed, the lens of the eyes becomes thin; the focal distance increases and thus enables us to work out the distant objects clearly. When the ciliary muscles contract, the attention lens becomes thicker and therefore the focal distance decreases, making nearby objects clearly visible. The human eye lens is ready to regulate its distance to look at both nearby and distant objects on the retina of the attention. This ability to regulate the focal distance is termed the ability of accommodation of the eyes. Therefore, Option b “because the eyes can easily adjust” is that the correct answer.
Option a “Because eyes have the camera in it” is wrong as there's no camera within the eyes. Eyes have a lens.
Option c “Because the eyes can become big and small” is wrong because the eyes almost remain the identical in size from our birth time. the scale hardly change by some (1-2) millimeters.
Option d “Because eyes are the foremost sensitive organ of the body” is invalid during this context. Eyes are sensitive organs but this has no relation with its ability to work out distant or nearby objects.