Fill in the blank with a suitable preposition.
David was very busy _______ the afternoon.
(a)with
(b)on
(c)at
(d)in

Hint: A preposition is a function word that combines with a noun or pronoun or noun phrase to form a prepositional phrase that can have an adverbial or adjectival relation to some other word.

Complete answer: In the given question, we have to find out which of the options given to us is related to the concept of time, as ‘afternoon’ is a time period that occurs during the middle of the day.
Let us thus analyze the options given to us in this question:
Option (a), 'with', refers to ‘in the company of; alongside, alongside of; close to; near to:’
Therefore, option (a) is incorrect as it is not related to a time period.

Option (b), ‘on', refers to ‘Positioned at the upper surface of, touching from above.’
Therefore, option (b) is incorrect as it is not related to a time period.

Option (c), ‘at', refers to ‘In or very near a particular place.’
Therefore, option (c) is incorrect as it is not related to a time period.

Option (d), ‘in', refers to ‘During (said of periods of time).’
Therefore, option (d) is correct as it is related to a time period.

Note: In this question, it will be helpful for the student to recall the concept of a time period. A time period is an amount of time, for example- a time period of 30 years; hastened the period of his recovery.