A 57-year-old woman with a 30-year x 2 pack/day history of cigarette smoking undergoes bronchoscopy. Biopsy of bronchial tissue shows replacement of the normal pseudostratified ciliated columnar epithelium with stratified squamous epithelium. This change represents:
A. dysplasia
B. hyperplasia
C. malignant transformation
D. metaplasia
E. necrosis and repair