We select blue light (415nm) and green light (540nm) for NBI because they are highly absorbed by (A)______, so that NBI is a function good for (B)_____with the high contrast.
(A): hemoglobin / (B): enhancing the image of capillary network
(A): cell in mucosa / (B): narrowing the focus of the lesion
(A): opening of glands / (B): enlarge the image of the pit pattern
(A): hemoglobin / (B): magnifying the image of blood vessel
(A): collagen / (B): enhancing the image of capillary network