Explanation
Each, each of, either and neither are distributive pronouns. ‘Each’ and ‘Each of’ are used to present the members of a group as individuals. Whereas ‘either’ and ‘neither’ are used when there is a comparison or choice between two things only. Since the given sentence is speaking about a group of patients, ‘either’ and ‘neither’ cannot be used. Thus options C and D are incorrect. On the other hand, ‘each’ is used for singular nouns like “each candidate” while ‘each of’ is used for plural nouns, such as “each of the kids”. Since the noun ‘patient’ is in singular ‘each’ is the suitable answer. Thus option A is correct, while option B is incorrect.
Please disable the adBlock and continue. Thank you.