Refer section 11.1.1 of your NCERT. What peculiarity does NCERT mention regarding diffusion and solids ?
1. It does not occur in solids
2. It is more easily visualized in solids
3. It requires expenditure of external energy and occurs against concentration gradient
4. Diffusion in solids rather than of solids is more likely.

Diffusion:
I. does not require any energy expenditure
II. is dependent on a living system
III. is a fast process
IV. is the only means for gaseous movements in plants
1. Only I and IV are correct
2. Only I, II and IV are correct
3. Only I, III and IV are correct
4. Only II and III are correct