The nurse is instructing the client on the correct way to take nitroglycerin as needed for chest pain:

Choice A reason: The Mantoux skin test, also known as the tuberculin skin test, measures the immune response to the tuberculin purified protein derivative injected into the skin. An induration of less than 1 mm is not considered a positive result. However, the size of the induration in the Mantoux test does not indicate whether the person is infectious or not.

Choice B reason: Negative sputum cultures for acid-fast bacillus (AFB) are a strong indication that the client is no longer infectious. Pulmonary tuberculosis is diagnosed and monitored by the presence of AFB in the sputum. When the sputum cultures are negative, it suggests that the client is not excreting the bacteria and is less likely to spread the infection to others.

Choice C reason: While no longer coughing up blood-tinged sputum is a sign of clinical improvement, it does not necessarily mean that the client is no longer infectious. The absence of blood in the sputum may indicate reduced inflammation or healing of lung tissue, but the client could still be capable of transmitting tuberculosis if AFB is present in the sputum.

Choice D reason: The Quantiferon-TB Gold test is a blood test that measures the immune response to Mycobacterium tuberculosis antigens. A positive result indicates that the person's immune system has been exposed to the bacteria, but it does not determine if the person is infectious. The term "positive (negative)" is contradictory and does not provide clear information about the client's infectious status.

Choice A reason: Petechiae on the chest are small, red or purple spots caused by bleeding into the skin and may be associated with various conditions, including infections. However, they are not a common finding in meningitis. Meningitis typically presents with symptoms related to inflammation of the meninges, the protective membranes covering the brain and spinal cord.

Choice B reason: Bradycardia, which is a slower than normal heart rate, is not a typical symptom of meningitis. While meningitis can affect various bodily functions, the classic symptoms are fever, headache, and neck stiffness, not changes in heart rate.

Choice C reason: Intermittent headache could be associated with meningitis, but the headaches that accompany meningitis are usually constant and severe due to the inflammation of the meninges. They are not typically described as intermittent.

Choice D reason: Photophobia, or light sensitivity, is a common finding in meningitis. The inflammation of the meninges can lead to an increased sensitivity to light, causing discomfort or pain when the patient is exposed to bright lights. This symptom, along with headache, neck stiffness, and fever, helps to distinguish meningitis from other conditions.