A client with leukemia has an absolute neutrophil count (ANC) of 760 mcL and temperature of 38.2°C after their chemotherapy treatment. When should the practical nurse initiate antibiotic therapy? a) Within one hour of onset of a fever b) After the causative agent is identified from the culture c) For long-term therapy over 3 months d) Once the fever drops below 38°C (100.4°F)