and B are :
A. `CH_(3)-underset(underset(18)OH)underset(|)overset(CH_(3))overset(|)C-underset(OH)underset(|)CH_(2),CH_(3)-underset(OH)underset(|)overset(CH_(3))overset(|)C-underset(OCH_(3))underset(|)CH_(2)`
B. `CH_(3)-underset(OH_(18))underset(|)overset(CH_(3))overset(|)C-underset(OH)underset(|)CH_(2),CH_(3)-underset(OH)underset(|)overset(CH_(3))overset(|)C-underset(OCH_(3))underset(|)CH_(2)`
C. `CH_(3)-underset(underset(18)OH)underset(|)overset(CH_(3))overset(|)C-underset(OH)underset(|)CH_(2),CH_(3)-underset(underset(18)OH)underset(|)overset(CH_(3))overset(|)C-underset(overset(18)OH)underset(|)CH_(2)`
D. `CH_(3)-underset(underset(18)OH)underset(|)overset(CH_(3))overset(|)C-underset(overset(18)OH)underset(|)CH_(2),CH_(3)-underset(OCH_(3))underset(|)overset(CH_(3))overset(|)C-underset(OH)underset(|)CH_(2)`