Somatoform disorder refers to a mental illness, Here, Alan is most likely to be diagnosed with somatoform disorder.
Somatoform disorder is also known as somatic symptom disorder.
It is a type of Mental disorder that shows as physical evidence that declares sickness or injury, but cannot be informed amply by an overall medical condition.
This is a variety of conditions which is a moral illness and also qualified by different types of symptoms such as body pain.
In the given case, there was no biological ground for Allan's disorder. This means the illness is a mental one and the convenience of symptoms.
Therefore, option D is correct.
Read more about Somatoform disorder, refer to:
https://brainly.com/question/8847202
