In the following question, the sentence given with blank to be filled in with…

Concept: A preposition is normally followed by a noun, pronoun, or gerund (a verb's '-ing' form functioning as a noun) - never by a bare base-form verb ('be') or a bare past participle ('given') standing on its own. When the understood subject of that verb is not the one performing the action but the one it is done TO, the gerund must be built in the PASSIVE voice: 'being + past participle' (for example 'being given', 'being told').

Application: In 'Rahul congratulated Neha on ___ the car', the gerund must come right after the preposition 'on'. Rahul is congratulating Neha on something that happened TO her - she received the car, she did not give it - so the understood subject of the gerund (Neha) is on the receiving end of the action. The gerund therefore has to be passive: 'being' supplies the '-ing' head the preposition needs, and 'given' (the past participle) shows the car was given to her.

Cross-check - why each other option fails:

• been given - a past-participle phrase; it needs an auxiliary such as 'having' (as in 'having been given') to function as a gerund, and 'on' cannot be directly followed by this bare participle form.

• be - the bare base form of the verb, used only in an infinitive ('to be') or a subjunctive clause; a preposition is never directly followed by this form.

• given - a passive past participle on its own; a preposition needs a genuine '-ing' gerund as its complement, and 'given' alone does not supply that '-ing' form.

Only 'being given' supplies a genuine '-ing' gerund immediately after 'on' while also keeping the passive sense that Neha is the one receiving the car, so it alone completes the sentence correctly.