Which sequence represents the correct mechanism of a Grignard reagent reacting with an ester?

Nucleophilic attack, formation of tetrahedral intermediate, elimination of alkoxide, second nucleophilic attack, protonation

Formation of enolate, nucleophilic attack, elimination, protonation

Elimination of alkoxide, nucleophilic attack, formation of tetrahedral intermediate, protonation

Nucleophilic attack, formation of carbocation, elimination of halide, protonation