What is the definition of mental disability according to the text? I- Significantly lower intellectual functioning than average, with manifestation...

What is the definition of mental disability according to the text?
I- Significantly lower intellectual functioning than average, with manifestation before the age of eighteen.
II- Limitations associated with two or more areas of adaptive skills.
III- The association of two or more disabilities.
IV- Difficulty in moving, generating effective reduction of mobility, flexibility, motor coordination, and perception.

a) Only I and II are correct.
b) Only II, III, and IV are correct.
c) Only I, II, and IV are correct.
d) All statements are correct.