The nth term formula is n²(n+1): 0²×1=0, 1²×2=2 (but we have 4), 2²×3=12 (but we have 18), 3²×4=36 (but we have 48), 4²×5=80 (but we have 100). Actually, the pattern is n(n+1)² with offset: 0×1²=0, 1×2²=4, 2×3²=18, 3×4²=48, 4×5²=100, so 5×6²=180. Option A (180) is correct.