Correct option is (B) Square
A cyclic parallelogram is a rectangle.
Hence, a cyclic rhombus is a square.
Alternative method :-
Let ABCD is a cyclic rhombus.
\(\therefore\) \(\angle A+\angle C\) \(=180^\circ\) and
\(\angle A=\angle C\)
\(\Rightarrow\) \(2\angle A\) \(=180^\circ\)
\(\Rightarrow\) \(\angle A\) \(=\frac{180^\circ}2=90^\circ\)
Since, if an angle in a rhombus is \(90^\circ\) then it becomes square.
\(\therefore\) ABCD is a square.
