a patient is getting heparin by intravenous infusion. the nurse received an order to increase the heparin infusion rate and obtain a partial thromboplastin time (ptt) in 1 hour. the ptt was drawn correctly and revealed a critically elevated level. the nurse was busy with another patient and failed to report the critical result to the physician within 30 minutes according to the facility's policy. subsequently, the patient sustained a massive intracerebral bleed. what type of negligence may be present? a. assessment failure b. planning failure c. communication failure d. evaluation failure