“Insatiable” means impossible to satisfy, as in, having an insatiable appetite or desire for something.
Option D is the correct answer because “unsatisfiable” means not capable of being satisfied, hence it is the correct answer.
Option A is incorrect because “undesirable” means not wanted or desirable because harmful, objectionable, or unpleasant, hence it is not the same as unsatisfiable.
Option B is incorrect because “irreconcilable” means so different from each other that they cannot be made compatible, hence it is incorrect.
Option C is incorrect because “unchanging” means something that isn’t changing , hence it is incorrect.