Final answer:
The smallest and most symmetrical teeth, which have a narrow mesiodistal root but a broad faciolingual root, are the Mandibular central incisors.
Step-by-step explanation:
The smallest and most symmetrical of all teeth, which are narrow mesiodistally but broad faciolingually, are the Mandibular central incisors (Option B). These teeth are among the eight incisors, four on the top and four on the bottom, that are used for biting into food.
In contrast, the maxillary central incisors are generally larger and the maxillary canines are known for having a pointed edge to tear up food, making them unsuitable as the smallest and most symmetrical of all teeth. Therefore, the correct answer to the question is the Mandibular central incisors.