A 67-year-old woman presents with multiple persistent large ulcers of her gingiva and buccal mucosa. Biopsy of tissue adjacent to the ulcers shows epithelial separation from submucosa through the level of the basement membrane. This is suggestive of which of the following?

a. Major aphthous ulcers
b. Secondary syphilis
c. Secondary herpes simplex infection
d. Pemphigus vulgaris
e. Mucous membrane pemphigoid

E