OptionMenu question

I'm trying to use the OptionMenu widget, but for some reason it's not defining it. I'm not sure if i'm doing anything wrong.

    def read_row(self) -> int:

        
        self.row_text =tkinter.StringVar()

        self.row_text.set('Num of rows:')

        row_label = tkinter.Label(
                master = self.root_window, textvariable = self.row_text,
                background = 'yellow', height = 1, width = 10, font = DEFAULT_FONT)

        row_label.grid(row=1, column = 0, padx = 10, pady=10, sticky = tkinter.W+tkinter.N)

        option = OptionMenu(self.root_window,self.row, 4,6,8,10,12,14,16)

        option.grid(row=1, column = 1, padx=10, pady = 10, sticky = tkinter.E+tkinter.N)
        return self.row.get()