The correct order of increasing bond length of C - H, C - O, C - C and C = C is

The C - H is the shortest due to small size of both atoms and large electronegativity difference. The double bonds are shorter than single bonds. Hence, C = C bond is shorter than C-O and C-C. Due to electronegativity difference between C and O, the C - O bond length is shorter than C-C bond. Hence, the correct order is
C-H < C = C < C-O < C-C