The correct option is C 1nm – 1000 nm
A colloid is a heterogeneous mixture in which one insoluble substance is dispersed throughout another substance at the microscopic level. Sometimes, the dispersed substance alone is called the colloid but whenever we use the term “colloidal suspension”, it refers to both the dispersed phase as well as the dispersion medium.
The particle dimension should be within the 1 nm-1000 nm range.