The standard notation of an atom is ${ }_{\text{Z}}^{\text{A}}\text{X}$ . The option which shows oxygen atom is

The general representation of an atom of element is ${ }_{\text{Z}}^{\text{A}}\text{X}$

Here, the letter ‘Z’ represents atomic number of an element .

The letter ‘A’ indicates mass number of element (protons + neutrons).

Hence, the correct symbol of oxygen is  ${ }_8^{16}\text{O}$.