The correct option is C 2-butene
One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of 44g/mol. The alkene is 2-butene.
Both the cis and trans form of 2-butene on ozonolysis give 2 moles of acetadehyde with the molecular mass of 44g/ mol. In this process of ozonolysis, ozone reacts with alkenes to break the double bond and forms two carbonyl groups. Hence, the correct answer is option (c).