Single furcation canal is seen in what percentage of mandibular molars: (A) 13%, (B) 10%, (C) 23%, (D) All of the above
Answer is A. There are three patterns for accessory canals in mandibular molars

Single accessory canal arises from coronal 1/3rd = 23%
Single furcation canal: 13%
Both accessory canal and Furcation canals : 10% of cases