Explanation:

- The original phrase is "the larger number of" people. It appears incorrect as "larger" implies a comparative form which is unnecessary in this context.

- Option 1: "the large number off" is incorrect because "off" is a typo and should be "of."

- Option 2: "No improvement required" is not suitable since the original phrase needs correction.

- Option 3: "an larger number of" is grammatically incorrect; "an" doesn’t fit before a word starting with a consonant.

- Option 4: "a large number of" is correct. This is a commonly used expression indicating a substantial quantity of people without comparing.