The correct answer id D. IgA monoclonal gammopathy.
The associated image and described biopsy findings are consistent with a diagnosis of pyoderma gangrenosum (PG), which most often presents as an acneiform papule or pustule that progresses into a rapidly expanding ulceration with an undermined border. ~50% of patients with PG have an underlying systemic condition, most commonly inflammatory bowel disease (ulcerative colitis more often than Crohn’s disease). Other associated conditions include: arthritis (typically asymmetric, seronegative, monoarticular arthritis of the large joints), leukemia (usually myelogenous), multiple myeloma, IgA monoclonal gammopathy, polycythemia, Hepatitis C infection, HIV infection, and systemic lupus erythematosus.
Celiac disease is associated with dermatitis herpetiformis. Ovarian cancer may underlie the development of dermatomyositis. Chronic pancreatitis is associated with pancreatic panniculitis. Lastly, paraneoplastic pemphigus may develop in patients with Castleman’s disease.
Reference: PMID: 26015785