Select the sentence in which the ‘-ing’ form of the verb expresses the continuity of an action/event.

Correct option is C

In option (c), the ‘-ing’ form of the verb "preparing" expresses the continuity of an action in progress.
· Grammatical Rule Used:
· The present continuous tense is formed using the auxiliary verb ‘am/is/are’ followed by the ‘-ing’ form of the main verb. It is used to indicate ongoing actions at the moment of speaking.
· Example: He is studying for the upcoming test.
Why other options are incorrect:
· (a) Reading novels is my favourite pastime: Here, "reading" is a gerund (noun), not expressing continuity.
· (b) I am fond of reading science fiction: Here, "reading" is a gerund, used to describe a hobby or liking.
· (d) The optician advised me to use reading glasses: Here, "reading" is an adjective describing the type of glasses.