Antitussive agents should be used with caution in patients who have a history of addiction.

Choice A rationale

Improved mental status can be a sign of better overall health but is not a specific indicator of improved heart failure status.

Choice B rationale

Using fewer pillows at night indicates reduced orthopnea, a common symptom of heart failure, suggesting that the patient’s heart failure status has improved.

Choice C rationale

Increased skin turgor indicates improved hydration status but is not a specific measure of heart failure improvement.

Choice D rationale

Heart rate regularity is important but does not directly indicate improved heart failure status.

Choice A rationale

CSF analysis and MRI are crucial in diagnosing multiple sclerosis (MS). CSF may show elevated levels of oligoclonal bands, indicative of immune system activity in the central nervous system. MRI can detect lesions or plaques in the brain and spinal cord, which are characteristic of MS.

Choice B rationale

Serum albumin and CT scan are not standard diagnostic tools for MS. Serum albumin is more relevant to liver function and nutritional status, while CT scans are less sensitive than MRIs in detecting MS lesions.

Choice C rationale

CSF proteins and angiography are not standard tests for diagnosing MS. While CSF protein levels might be altered in MS, angiography is used to visualize blood vessels and is not relevant to MS diagnosis.

Choice D rationale

Serum anti-acetylcholine antibodies and x-rays are not used to diagnose MS. Anti-acetylcholine antibodies are related to myasthenia gravis, and x-rays are not useful for visualizing MS lesions.