Final answer:
In the given sentence, 'The boys will go to school on Wednesday,' the proper noun is 'Wednesday'. A proper noun is a name given to individual, specific entities and they always start with a capital letter in English.
Step-by-step explanation:
In the sentence, 'The boys will go to school on Wednesday,' the proper noun is d) Wednesday. A proper noun is a specific name given to individual people, places, companies, or things. Proper nouns always start with a capital letter in English. Here, Wednesday refers to a specific day of the week, and thus, is a proper noun. Other examples of proper nouns could be the names of individuals like 'Susan' or 'Harry', the name of a place like 'New York', or an organization like 'Microsoft'.
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