An ideal gas is subjected to cyclic process involving four thermodynamic states, the amounts of heat \((Q)\) and work \((W)\) involved in each of these states are \(\begin{aligned} & Q_1=6000 \mathrm{~J}, \quad Q_2=-5500 \mathrm{~J} ; Q_3=-3000 \mathrm{~J} ; \ & Q_4=3500 \mathrm{~J} \ & W_1=2500 \mathrm{~J} ; \quad W_2=-1000 \mathrm{~J} ; \quad W_3=-1200 \mathrm{~J} ; \ & W_4=x \mathrm{~J} . \end{aligned}\) The ratio of the net work done by the gas to the total heat absorbed by the gas is \(\eta\). The values of \(x\) and \(\eta\) respectively are

1. A \(500 ; 7.5 \%\)
2. B \(700 ; 10.5 \%\)
3. C \(1000 ; 21 \%\)
4. D \(1500 ; 15 \%\)