Name the type of volcano illustrated in diagram B and describe how it forms?

Without access to the specific diagram B you mentioned, I can provide a general answer. If the diagram illustrates a shield volcano, it forms primarily from the eruption of low-viscosity basaltic lava that flows over long distances, creating a broad, gently sloping profile. Over time, repeated eruptions build up the volcano's layers, resulting in its characteristic shape. If the diagram depicts a stratovolcano, it forms through alternating layers of lava flow and explosive volcanic ash, creating a steeper, conical structure.