In pregnancy following change takes place -

Ans. is 'a' i.e., Tidal volume increase Respiratory changes during pregnancyo TLC is reduced by 5%o Subcostal angle increases from 69 to 103.o Tidal volume increases.o PaCO2 fall from 38 to 32 mnvhg & PaO2 rises from 95 t0 105 mm/hgo Pregnancy is a state of respiratory alkalosis.o Cardiac output increases during pregnancy, (already explained)