The correct order which describes the true solution, colloidal solution and suspension in the order of their increasing stability is
Suspension< colloidal solution< true solution
The explanation for the correct option:
(a) Suspension< colloidal solution< true solution:
The explanation for the incorrect options:
Since, the correct order in increasing the stability is suspension< colloidal solution< true solution thus options (b), (c) and (d) are incorrect.
Hence, option (a) is the correct option.