Match List I with List II and select the correct answer:
List I (NC machine tool system)
A. NC system
B. CNC system
C. DNC system
D. Machining centre
List II( Features)
1. It has an integrated automatic tool changing unit and a component indexing device
2. A number of machine tools are controlled by a computer. No tape reader, the part programme is transmitted directly to the machine tool from the computer memory
3. The controller consists of soft-wired computer and hard-wired logic system. Graphic display of tool path is also possible
4. The instructions on tape is prepared in binary decimal form and operated by a series of coded instructions
Codes:
A B C D
(a) 4 2 3 1
(b) 1 3 2 4
(c) 4 3 2 1
(d) 1 2 3 4