<prompt> Incidence of C shaped canal is maximum for:Mandibular 1st molarMandibular 2nd molarMaxillary 1st premolarMaxillary 1st molar  <response>: Some C-shaped canals are difficult to interpret on radiographs and often are not identified until an endodontic access is made. These are commonly seen in mandibular second molars and maxillary first molars, especially when roots of these teeth appear very close or fused. 