An ester (A) with molecular formula C$_9$H$_{10}$O$_2$ was treated with excess of CH$_3$MgBr and the complex so formed was treated with H$_2$SO$_4$ to give an olefin (B). Ozonolysis of (B) gave a ketone with molecular formula C$_8$H$_8$O which shows positive iodoform test. The structure of (A) is: