Ans : \((\mathbf{B}, \mathbf{D})\)
There seems to be a printing mistake here
If there are \((2 n-1)\) terms instead of \((2 n+1)\) terms then \(n^{\text {th }}\) terms of the A.P., G.P. and H.P. are the A.M., G.M. \& H.M
of the first and the last terms.
So, \(a \geq b \geq c \& a c-b^{2}(B, D)\)
otherwise if there are \((2 n+1)\) terms then the \(n^{\text {th }}\) terms should be in decreasing order of A.P., G.P. \& H.P.
i.e. \(\mathbf{a} \geq \mathbf{b} \geq \mathbf{c}\). (B)