The answer would be B. Dome-Type. V-Type engines are some of the most common, with abbreviations such as V6, V8, etc. In-Line engines are where the cylinders are in a straight line. Horizontally opposed engines or 'flat' engines are where the cylinders are on a flat plane. Therefore the only type of engine *configuration* is B. Dome-Type.
Dome-type relates to the cylinder design, where the piston has a convex dome to maximize the efficiency.
Hope this helps.
