In the following question, a sentence is given with a phrase highlighted in bold. Select the option given below that can replace the phrase in bold to make the sentence grammatically and contextually correct and mark that as your answer. If the sentence is correct as it is, mark 'no improvement required', as the answer The janitor got rid of a large number of dust from the hallway to maintain cleanliness and hygiene.

(b) The error in the original sentence lies in the use of the phrase "a large number" before the word "dust." The phrase "a large number" is typically used to quantify countable nouns, such as "a large number of people" or "a large number of books." However, in the given context, "dust" is not counted individually; instead, it is considered a mass or uncountable noun. Therefore, the more appropriate phrase to use with "dust" is "a large amount of," which is used to quantify mass or uncountable nouns. Option (b) is correct because it effectively addresses the error in the original sentence by replacing "a large number" with "a large amount." This correction accurately conveys the quantity of dust being removed by the janitor. Options (a) and (c) do not rectify the error present in the original sentence. These options continue to use the wrong expression 'large number' with the uncountable noun 'dust'. The error in option (d) lies in the phrase "will required." The verb "required" is in the past tense, but it should be in the present tense ("require") to match the auxiliary verb "will." When using the auxiliary verb "will" to indicate future tense, the main verb should be in its base form rather than in the past tense form. Hence, (b) is the correct answer. The correct sentence is: The janitor swept a large amount of dust from the hallway to maintain cleanliness and hygiene.