If a, b, c are in GP where a > 0, b > 0, c > 0 , then which of the...

$$\begin{array}{ll}\because & \mathrm{a}, \mathrm{b}, \mathrm{c} \text{are in G.P } \\ \therefore \quad b^2=a c\end{array}$$$Squaring both sides$$\begin{aligned} & \left(b^2\right)^2=a^2 c^2 \\ & \therefore \quad a^2, b^2, c^2 \text{ are\text{ in } G.P }\end{aligned}$$From(i)$\left(\frac{1}{b}\right)^2=\frac{1}{a} \times \frac{1}{c}$\therefore \quad$\frac{1}{a}, \frac{1}{b},\frac{1}{c}$are in G.P From(i)$b=\sqrt{a c} \Rightarrow(\sqrt{b})^2=\sqrt{a} \sqrt{b}[\because a \gt 0, b \gt 0 and c \gt 0]\therefore \quad \sqrt{a}, \sqrt{b}, \sqrt{c}$ are in G.P.