A 48-year-old male undergoes excision of a chronic pilonidal sinus with a rhomboid-shaped defect over the sacrococcygeal region. The reconstructive plan involves a local flap designed adjacent to the defect, where the flap is transposed into the primary defect and the donor site is closed primarily. The flap follows the lines of minimal skin tension and relies on subdermal vascular supply without a named artery. What is the correct classification of this flap?
A. Rotation flap
B. Axial pattern transposition flap
C. Random pattern transposition flap
D. Advancement fasciocutaneous flap