Is it reasonable to assume that at the given states the substance behaves as an ideal gas?

a. Oxygen at 30◦C, 3 MPa

b. Methane at 30◦C, 3 MPa

c. Water at 30◦C, 3 MPa

d. R-134a at 30◦C, 3 MPa

e. R-134a at 30◦C, 100 kPa