6365. That the plan is both inhuman and preposterous needs no further proof.

✅ The correct answer is option C.
heartless : displaying a complete lack of feeling or consideration.

impractical : not adapted for use or action; not sensible or realistic.

absurd : wildly unreasonable, illogical, or inappropriate.

abnormal : deviating from what is normal or usual, typically in a way that is undesirable or worrying.

preposterous : contrary to reason or common sense; utterly absurd or ridiculous.

Synonym of preposterous is absurd