The capacitance of two condensers in parallel is four times their capacitance when they are connected in series. The ratio of the individual capacitances will be

1 : 1

The correct answer is Option 2: 1:1

$C_1+C_2=4 \frac{C_1 C_2}{C_1+C_2}$

$\left(C_1+C_2\right)^2=4 C_1 C_2$

$C_1^2+2C_1 C_2+C_2^2=4C_1 C_2$

$C_1^2-2C_1 C_2+C_2^2=0$

$\left(C_1+C_2\right)^2=0\Rightarrow C_1=C_2$