what would be the mechanism for each of these answer choices?

14-14 Which of the reaction schemes below gives 1,4-pentadien-3-ol, H,C-CHCH(OH)CH-CH, as the major organic product and with minimal byproduct formation? 1) HC-CHCHCH-CH2 + H20 (solvolysis) Br 2 HC-CHMgBr + HCOCH_CH, folowed by neutralization 3) H,C-CHMgBr + H2C-CHCOH HC-CH2O 0 II 4) H4C-CHMgBr (x) + CH CH OCOCH2CH, followed by neutralization