Consider the machines,
M1 - a NPDA accepting L1,
M2 - a 2 way PDA accepting L2,
M3 - a PDA with two stacks accepting L3.
Choose the false statement,
1) For any CFL L, there exists some M1, M2 and M3.
2) For some CSL L, there exists some M1,M2 and M3.
3) For every recursive set, there exists some M1,M2 and M3.
4) The power of the machines are not M1 <= M2 < M3.
