To determine the correct answer, we need to identify the preposition that correctly indicates the time frame in which the author wrote the book.
The options are:
A: of
B: off
C: on
D: in
Let's analyze each option and determine which one is the most appropriate:
A: of
- The preposition "of" is used to indicate possession or belonging, but it does not indicate a specific time frame. Therefore, option A is incorrect.
B: off
- The preposition "off" is used to indicate separation or movement away from a place or position. It does not convey the idea of writing a book within a specific time frame. Therefore, option B is incorrect.
C: on
- The preposition "on" is used to indicate a specific day or date, but it does not convey the idea of a time frame lasting several weeks. Therefore, option C is incorrect.
D: in
- The preposition "in" is commonly used to indicate a time frame or duration. It can be used to indicate that an action took place within a specific period. In this case, the author wrote the book "in" five weeks, which means that the writing process lasted for a duration of five weeks. Therefore, option D is the correct answer.
In conclusion, the correct answer is D: in as it accurately conveys the idea that the author wrote the book within a specific time frame of five weeks.

The correct answer is option 'D' - in.

Explanation:

- The verb "wrote" is in the past tense, indicating that the action has already taken place.
- The phrase "five weeks" indicates the duration of time it took to write the book.
- The preposition "in" is used to express a period of time during which an action occurs.
- When we say "wrote the book in five weeks," it means that the author completed the writing process within a timeframe of five weeks.

Let's break down the answer into headings and key points:

b The Verb 'Wrote' and Past Tense
- The verb "wrote" is used to indicate the action of writing the book.
- The past tense form of the verb is used because the action has already occurred.

b The Phrase 'Five Weeks'
- The phrase "five weeks" specifies the duration of time it took to complete the writing process.

b The Preposition 'In'
- The preposition "in" is used to express a period of time during which an action occurs.
- In this case, it is used to indicate the duration of time it took to write the book.

b Putting It All Together
- When we say "wrote the book in five weeks," we mean that the author completed the writing process within a timeframe of five weeks.
- The sentence implies that the author started writing and finished writing the book within the span of five weeks.

In conclusion, the correct preposition to use in the sentence is 'in' because it accurately expresses the duration of time it took for the author to write the book.