Option (d) is correct
The component NaHCO3 can only produce CO2 on heating of the given mixture as per following balanced equation
2NaHCO3-> Na2CO3+H2O+ CO2
This equation reveals that 22.4 L CO2 is produced from 2 moles or 2(23+1+12+3*16)=168g NaHCO3
So 1.12L of CO2 can be obtained from 168/22.4x1.12=8.4g of NaHCO3
So the wt of Na2CO3 in the mixture of 19g before heating was = 19-8.4=10.6g