If Two Resistors with Resistances $R_{1}$ And $R_{2}$ Are Connected in Parallel, as in the Figure, Then the in Parallel

Multiple Choice

If two resistors with resistances $R_{1}$ and $R_{2}$ are connected in parallel, as in the figure, then the total resistance $R$ measured in ohms ( $\Omega$ ) , is given by $\frac{1}{R}=\frac{1}{R_{1}}+\frac{1}{R_{2}}$ . If $R_{1}$ and $R_{2}$ are increasing at rates of $0.1 \Omega / s$ and $0.2 \Omega / s$ respectively, how fast is $R$ changing when $R_{1}=75$ and $R_{2}=100$ ?
Round the result to the nearest thousandth.

A) $0.1596 ~\Omega / \mathrm{s}$
B) $1.1974 ~\Omega / \mathrm{s}$
C) $0.1454 ~\Omega / \mathrm{s}$
D) $0.0694 ~\Omega / \mathrm{s}$
E) $0.1688 ~\Omega / \mathrm{s}$