A patient who takes haloperidol (Haldol) 10 mg/day orally developed restlessness, agitation, and an ...

A patient who takes haloperidol (Haldol) 10 mg/day orally developed restlessness, agitation, and an inability to sit still
 
  The nurse then administered a PRN dose of haloperidol 5 mg intramuscularly. One hour later the patient's symptoms were worse. What is the most likely explanation?
  a. The PRN medication has not yet taken effect.
  b. The patient needs an additional PRN dose of haloperidol to control the rising agitation.
  c. The patient was experiencing akathisia, which worsened after receiving the PRN medication.
  d. The nurse should consider an adjunctive dose of an antianxiety drug such as lorazepam (Ativan).