Which of the following are correct regarding the definition of a technical stage?
1. Technical stages never overlap
2. They are typified by the use of a particular set of specialist skills

3. Cover elements such as design, build and implementation
4. The work can be grouped by the set of techniques used

A.
1,2,3

B.
1,2,4

C.
1,3,4

D.
2,3,4