\(The\ volume\ of\ the\ prism:V=A_B\cdot H\\\\A_B-area\ of\ the\ base;\ H-height\ of\ the\ prism\\-------------------------------\\\\In\ base\ is\ the\ triangle.\ The\ area\ of\ the\ triangle:A_\Delta=\frac{b\cdot h}{2}\\\\b-the\ basel\ h-the\ height\\\\b=14cm;\ h=4cm\\\\subtitute:A_\Delta=\frac{14\cdot4}{2}=\frac{56}{2}=\boxed{28\ (cm^2)}\\\\Answer:V=28\cdot15=\boxed{420\ (cm^3)}\leftarrow\boxed{\boxed{C}}}\)
