I. L1 ∪ L2 is context-free = CFL ∪ CFL = CFL So, True
II. ¯L1 is context-free = ¯¯¯¯¯¯¯¯¯¯¯¯CFL=CSL but not CFL. So, False
III. L1−R is context-free = CFL ∩ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯Regular = CFL. So, True
IV. L1 ∩ L2 is context-free = CFL ∩ CFL = CSL. So,False