The correct answer is D. 23541.
The first word, “books,” is a plural noun. The second word, “I,” is a pronoun. The third word, “some,” is an adjective. The fourth word, “buy,” is a verb. The fifth word, “shall,” is a modal verb.
The correct order of the words is “I shall buy some books.” This is because the subject of the sentence is “I,” and the verb is “shall buy.” The object of the sentence is “some books.”
The other options are incorrect because they do not follow the rules of English grammar. For example, option A, “25413,” would make the sentence “books shall I buy some.” This is not a grammatically correct sentence because the subject and verb do not agree in number. Option B, “25431,” would make the sentence “shall I buy some books.” This is also not a grammatically correct sentence because the subject and verb do not agree in number. Option C, “23145,” would make the sentence “some books I shall buy.” This is not a grammatically correct sentence because the subject and verb do not agree in number.