The correct answer is E. Melanocytic nevi.

Melanocytic nevi is not a common cause of multiple dermatofibromas. Although some dermatofibromas are thought to arise at sites of trauma or arthropod bites, their precise etiology is not known. Multiple eruptive dermatofibromas have been observed in patients with autoimmune disorders such as lupus erythematosus and atopic dermatitis and in the setting of immunosuppression (i.e. HIV infection). Clinically, dermatofibromas can be confused with cysts or melanocytic nevi, especially those with fibrosis. However, melanocytic nevi are not a common cause of multiple dermatofibromas. 

1 – HIV infection: Multiple eruptive dermatofibromas have been observed in patients with autoimmune disorders such as lupus erythematosus and atopic dermatitis and in the setting of immunosuppression (i.e. HIV infection). 2 – Systemic lupus erythematosus: Multiple eruptive dermatofibromas have been observed in patients with autoimmune disorders such as lupus erythematosus and atopic dermatitis and in the setting of immunosuppression (i.e. HIV infection). 3 – Arthropod bites: Some dermatofibromas are thought to arise at sites of trauma or arthropod bites. 4 – Atopic dermatitis: Multiple eruptive dermatofibromas have been observed in patients with autoimmune disorders such as lupus erythematosus and atopic dermatitis and in the setting of immunosuppression (i.e. HIV infection).

References:

Bolognia, Jean, et al. Dermatology. Elsevier, 2018; Yazici AC, Baz K, Ikizoglu G, Koca A, Kokturk A, Apa DD. Familial eruptive dermatofibromas in atopic dermatitis. J Eur Acad Dermatol Venereol. 2006;20(1):90-92. doi:10.1111/j.1468-3083.2005.01357.x; Beatrous SV, Riahi RR, Grisoli SB, Cohen PR. Associated conditions in patients with multiple dermatofibromas: Case reports and literature review. Dermatol Online J. 2017;23(9):13030/qt8zv852d8. Published 2017 Sep 22.