Gerd Muller is the correct answer. He scored two hat-tricks in the 1970 World Cup for West Germany - one against Bulgaria and another against Peru. He was a prolific striker and holds this record for most hat-tricks in a single World Cup tournament.
Gerd Muller scored two separate hat-tricks for West Germany during the 1970 World Cup (against Bulgaria and Peru), part of his tournament-high 10 goals. None of the other names were strikers who scored multiple goals in that tournament, let alone two hat-tricks.