What is the major distinction between a somatoform disorder and a psychophysiological illness?

a. A somatoform disorder has no identifiable physical cause, while psychophysiological illnesses do have physical explanations and are made worse by the presence of psychological stress.
b. Somatoform disorders and psychophysiological illnesses are two names for the same condition. The former is the label that used to be applied, with the latter being the current correct term.
c. A psychophysiological illness has no identifiable physical cause, while somatoform disorders do have physical explanations and are made worse by the presence of psychological stress.
d. Somatoform disorders last for up to 3 months. After 3 months, the diagnosis is changed to a psychophysiological illness.

Answer: A