Each of the following questions consists of 4 figures marked 1, 2, 3 and 4 called the Problem Figures followed by 4 other figures . Select a figure from amongst the Answer Figures which will continue the same series as established by the four Problem Figures.

One blank segment of triangle is darkened in each step in clockwise.

Rectangle rotates 90 degree left in each step.

One blank segment of rectangle is darkened in each step in anti-clockwise.

Thus, correct option is (a).