Match the output signals as obtained from four measuring devices in response to a unit step change in the input signal.
$\begin{array}{cc}\
&\text{P. Gas chromatograph, with a long capillary tube} \\
&\text{Q. Venturi tube} \\
&\text{R. Thermocouple with first order dynamics} \\
&\text{S. Pressure transducer with secondorder dynamics}\\
\\ \end{array}$
- $P-IV,\:Q-III,\:R-II,\:S-I$
- $P-III,\:Q-I,\:R-II,\:S-IV$
- $P-IV,\:Q-I,\:R-II,\:S-III$
- $P-II,\:Q-IV,\:R-III,\:S-I$