A patient on antipsychotics complains of severe restlessness, inability to sit still, and constant pacing. This adverse effect is best described as:

Correct option is A

Akathisia is a subjective feeling of restlessness with objective inability to stay still. It is an extrapyramidal side effect of antipsychotics, usually treated with propranolol.
Explanation of options: (a) ✔ Correct; classic description of akathisia. (b) ✘ Acute dystonia = sudden sustained muscle contractions, not restlessness. (c) ✘ Parkinsonism = rigidity, tremors, bradykinesia. (d) ✘ Tardive dyskinesia = late-onset involuntary chewing/lip smacking.