Which of the following are the essentials of any good lighting system?
(a) Adequate illumination of suitable color on the working surfaces.
(b) Avoidance of hard shadows
(c) Avoidance of glare
(d) Maintenance free
1
(b), (c) and (d)
2
(a), (b) and (c)
3
(a), (b), (c) and (d)
4
(a), (b) and (d)