Choose the appropriate preposition for the given sentence: Our prices are subject ______ a heavy discount.

There are some verbs/nouns/adjectives which are followed by fixed prepositions as given below: ​Exonerate from, refrain from, subject to, based on, aptitude for, inured to, accused of, predilection for, respite from, vexed at, etc. Example: ​After spending some time on the island, they became inured to the hardships.​ ​Hence, according to the phrases given above, 'to' will be the correct choice. The given phrase 'subject to' means cause or forced to undergo (a particular experience of a form of treatment). Correct Sentence: Our prices are subject to a heavy discount.