Step 1: Mania is a mood episode marked by elevated, expansive, or irritable mood lasting at least one week, with increased energy and activity. A core feature is inflated self-esteem or grandiosity.
Step 2: The manic patient typically shows high self-esteem, reduced need for sleep, pressured speech, flight of ideas, distractibility, and excessive involvement in risky pleasurable activities.
Step 3: Paranoid delusion can appear in severe mania with psychotic features, but it is not a defining or universal characteristic. Loss of orientation (disorientation in time, place, or person) is a feature of delirium or organic states, not of uncomplicated mania, where sensorium remains clear.
Step 4: The single feature that best and consistently characterises mania is high self-esteem (grandiosity), so option C is correct, and "All" is wrong because loss of orientation does not belong.