Which of the following is a life-threatening, prolonged asthma attack that does not respond to the usual treatment?

A. Nocturnal asthma – This refers to asthma symptoms that worsen at night, often due to circadian changes in airway tone, but it is not inherently life-threatening or unresponsive to treatment. B. Extrinsic asthma – Also known as allergic asthma, this form is triggered by allergens like pollen or dust and is generally responsive to standard treatments. C. Status asthmaticus – This is a life-threatening condition involving a severe, prolonged asthma attack that does not respond to routine bronchodilator therapy and requires emergency intervention. D. Intrinsic asthma – Also called non-allergic asthma, this type is triggered by factors like stress, cold air, or infections, but it is not defined by treatment resistance or severity alone.