Puzzle-2 (CSAT-2011)

Consider the figure given below and answer the question that follows:

What is the minimum number of colours required to paint the figure given

above such that no two adjacent regions have the same colour?
(a) 2        (b) 3           (c) 4            (d) 5

Solution follows here:

Solution:

As shown in the figure, only 3 colours are                   sufficient.
Answer option (b)