Final answer:
The correct synonym for 'preposterous' is 'ridiculous', as both words describe something that is absurd or invites mockery.
Step-by-step explanation:
The word preposterous is an adjective, which means something that is utterly absurd or ridiculous. To find a synonym for the word 'preposterous', we should look for another adjective that conveys a similar meaning of being senseless or unreasonable. When we consider the options provided:
- unexpected - This generally means something surprising or not anticipated.
- prominent - This refers to something that stands out or is noticeable, not necessarily absurd.
- courageous - This means having courage, which is unrelated to absurdity.
- ridiculous - This means deserving or inviting mockery or derision, which is quite similar in meaning to preposterous.
Therefore, the correct synonym for preposterous is d) ridiculous.