Final answer:
The nurse should expect to see an increased respiratory rate (option c) in a 6-month-old infant with bacterial pneumonia, as this is a compensatory mechanism to maintain adequate oxygen levels in the presence of lung inflammation and mucus accumulation.
Step-by-step explanation:
When assessing a 6-month-old infant who has bacterial pneumonia, a nurse can expect to observe certain clinical manifestations due to the infection and inflammation in the lungs. Among the options provided, c) Increased respiratory rate is a classic sign of pneumonia in infants. Pneumonia often leads to an increased respiratory rate as the body attempts to compensate for reduced lung function and hypoxemia. This is a response to the lungs filling with mucus and the subsequent difficulty in obtaining sufficient oxygen, as evidenced by similar cases where patients developed a productive wet cough, and dyspnea, and required comprehensive assessment including a chest radiograph showing a "shadow" indicative of pneumonia.