<prompt> In which of the following forms of pulmonary carcinoma is the classic progression of metaplasia to dysplasia to carcinoma in situ observedSmall-cell carcinomaAdenocarcinomaLarge-cell carcinomaSquamous cell carcinoma  <response>: All stages from squamous metaplasia to carcinoma in situ are observed in squamous cell carcinoma. Such a clear progression is not seen in the other forms of cancer listed. 