Choose the option which best correct the given phrase-
This is Milton’s, the poet's cottage.
a) No change
b) This is Milton, the poet's cottage.
c) This is Milton's, the poet cottage.
d) This is the Milton, the poet cottage.

Hint:The error in this question is of an apostrophe 's'. It has to be correctly placed, with correct usage and logical sequence of it. It comes under punctuation errors.

Complete answer:
The sentence says that the poet's cottage is named 'Milton'. Now, we have to correctly frame it with the correct apostrophe 's'. The difference between putting the apostrophe before the -s or after the -s changes the meaning and usage of the word. There are also some exceptions and other things to keep in mind when making a noun possessive.
Now, let us examine all the given options to find out the correct option -
Option 'a' - This option will be chosen only if all the other three options are incorrect, or are not suitable for the given question.
Option 'b' - This is the correct option as the '-s' will be used only after 'poet', and not 'Milton'. So, this is grammatically and logically correct.
Option 'c' - This option is not the correct option as it is not grammatically and logically correct. The '-s' wouldn't be used after 'Milton'.
Option 'd' - This is also an incorrect option as both 'Milton' and 'poet' don't have an apostrophe 's'. So, we will eliminate this option.
As we have analyzed all the given options, we can easily figure out the correct answer. Here, the correct phrase would be - This is Milton, the poet's cottage. Hence, option 'b' is the correct option.

Note:
For nouns in apposition, we add the 's to the second element only. In this sentence, the phrase 'the poet' is the appositive to the noun 'Milton'. The second element is 'the poet'.