What is the purpose of including a control group in

Select the option figure in which the given figure is embedded (rotation is not allowed).

Select the answer figure in which the question figure is hidden ?

From the given answer figures, select the one in which the question figure is hidden / embedded(rotation is not allowed).

In each of the following questions from the given answer figures, select the one in which the question figure is hidden/embedded.

Find out which of the figures (1), (2), (3) and (4) can be formed from the pieces given in figure  (X) .

Find out the alternative figure which contains the given figure as its part.

Select the option in which the given figure is embedded.

Select the option in which the given figure is embedded.