Which one of the following circuits is NOT equivalent to a $$2$$-input $$XNOR$$ (exclusive NOR) gate

The simplified $$SOP$$ (Sum of product) form of the Boolean expression
$$\left( {P + \overline Q + \overline R } \right).\left( {P + \overline Q + R} \right).\left( {P + Q + \overline R } \right)$$ is

Consider the following circuit involving three Dtypes flip-flops used in a certain type of Counter configuration.

If all the flip-flops were reset to $$0$$ at power on, what is the total number of distinct outputs (states) represented by $$PQR$$ generated by the counter?

Consider the following circuit involving three Dtypes flip-flops used in a certain type of Counter configuration.

If at some instance prior to the occurrence of the clock edge, $$P, Q$$ and $$R$$ have a value $$0,1$$ and $$0$$ respectively, what shall be the value of $$PQR$$ after the clock edge?