Questão de Língua Inglesa

Which option completes the text below correctly? There are cells in the retina of our eye that ___ directly with the brain's biological clock regulators located in the hypothalamus and this pathway is most affected by light. These neurons ---,-- to be most affected by light waves from the blue spectrum or blue light. This is the kind of light most prominent in electronic lights from computers and smartphones. This ___ a modem challenge that can adversely affect our natural sleep-wake cycle. Additional factors that can hamper sleep ___ pain conditions, medications for other conditions, and the increased demands and connectedness of modem society. (Adapted from http://theconversation.com)