Conversion disorder as the name indicates it the conversion of psychological stress into a physical stress. This actually occurs after an injury but there will be no sign of physical injury. The classic symptom of this disorder is the la belle indifference.
La belle indifference is defined as the substantial emotional indifference the presence of the dramatic physical symptoms.
Hence the option c is not correct.
Illness anxiety disorder as the name indicates it is the excessive worry about the health and easily become alarmed about the possibility of having an illness. They cannot tolerate or reassured if they are well and always elicit negative reactions from the physicians.
Hence the option a is not correct.
Not all worries on health are regarded as illness anxiety disorder. Some people also suffer from transient hypochondriasis that is a result of contracting an actual illness or life threatening illness or obtained even from caring someone with a medical condition.
Hence the correct option is .