A compound, containing only carbon hydrogen and oxygen, has a molecular mass of 44. On complete oxidation, it is converted into a compound of molecular weight 60. The original compound is

 The molecular weight of compound $=44$

Molecular of compound after oxidation is $=60$

The difference in molecular weight is $60-44=16$

The complete oxidation product is a carboxylic acid. One oxygen atom less will be aldehyde.

So, the original compound is an aldehyde.

Therefore, option A is correct.