The correct answer is C. Along the lines of blaschko.

This is an epidermal nevus. Epidermal nevi are a heterogenous group of mosaic lesions that are typically distributed along the lines of blaschko and can be located anywhere on the body (trunk, extremities, face and scalp). Clinically they can appear smooth, warty or barely palpable. Even the color of epidermal nevi can vary from being flesh colored to tan, brown or pink.

Accessory nipple is typically seen along the milk line.

Epidermal nevi of the non-verruocous, epidermolytic variant can be seen on the palmo-plantar aspect in the setting of Pachonychia Congenita (the local variant of palmo-plantar keratoderma).

A myriad of both malignant and non-malignant entities can be seen on the extremities and trunk, including epidermal nevi.

For this answer choice, lines of blaschko mosaicism is the most specific answer choice for epidermal nevi.

References:
Bolognia J, Cerroni L, Schaffer JV. Dermatology. Philadelphia: Elsevier; 2018. Chapter 62.