The correct statement(s) about the compound H3C(HO)HCCH=CHCH(OH)CH3 (X) are:

Since a carbon-carbon double bond is present, the molecule can have either cis isomer or trans isomer. In cis isomer (which is symmetrical), the number of enantiomers is 2n = 22 = 2. The number of meso compounds possible is 2(n/2) = 2(2/2) = 1. Hence, the total number of optical isomers possible is 2+1=3. Trans isomer is also symmetrical. Hence, the total number of optical isomers possible for trans isomer is also 3. Hence, the total number of stereoisomers possible for X is 3+3=6. Hence, the option A is correct and the option B is incorrect. If the stereochemistry about the double bond in X is trans, the number of enantiomers possible for X is 4. Thus, the option C is incorrect. If the stereochemistry about the double bond in X is cis, the number of enantiomers possible for X is 2. Thus, the option D is correct.