$\mathrm{HO}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{O}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{OH}$  is the correct structure with 2 P - OH, 2 P - H, and 2 P = O bonds. The drawn structure on the board is incorrect.

$\mathrm{HO}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{O}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{OH}$  is the correct structure with 2 P - OH, 2 P - H, and 2 P = O bonds. The drawn structure on the board is incorrect.

$\mathrm{HO}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{O}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{OH}$  is the correct structure with 2 P - OH, 2 P - H, and 2 P = O bonds. The drawn structure on the board is incorrect.

$\mathrm{HO}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{O}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{OH}$  is the correct structure with 2 P - OH, 2 P - H, and 2 P = O bonds. The drawn structure on the board is incorrect.

$\mathrm{HO}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{O}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{OH}$  is the correct structure with 2 P - OH, 2 P - H, and 2 P = O bonds. The drawn structure on the board is incorrect.

$\mathrm{HO}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{O}-\stackrel{\underset{\parallel }{O}}{\underset{\stackrel{|}{\mathrm{H}}}{\mathrm{P}}}-\mathrm{OH}$  is the correct structure with 2 P - OH, 2 P - H, and 2 P = O bonds. The drawn structure on the board is incorrect.