A good quality of steel is to be made by mixing two low quality steel in ratio 1 : 2. The ratio of carbon and iron in first type of steel is 2 : 3 and that in second type of steel is 1 : 3. What is the ratio of carbon and steel in the good quality steel?

a) 1 : 3
b) 3 : 7
c) 2 : 5
d) 2 : 3