The correct option is
A −4,−3,−83,−2,−1,+3,+4For compounds containing
C atoms, the oxidation number of
C atom
=2nO−nHnCHere, nO,nH and nC represents the number of oxygen, hydrogen and carbon atoms respectively.
For CH4, the oxidation number of C atom =2nO−nHnC=0−41=−4
For C2H6, the oxidation number of C atom =2nO−nHnC=0−62=−3
For C3H8, the oxidation number of C atom =2nO−nHnC=0−83=−8/3
For C2H4, the oxidation number of C atom =2nO−nHnC=0−42=−2
For C2H2, the oxidation number of C atom =2nO−nHnC=0−22=−1
For H2C2O4, the oxidation number of C atom =2nO−nHnC=2×4−22=+3
For CO2, the oxidation number of C atom =2nO−nHnC=2×2−01=+4
Thus, the oxidation number of C in CH4,C2H6,C3H8,C2H4,C2H2,H2C2O4 and CO2 is −4,−3,−83,−2,−1,+3 and +4 respectively.