Who in Pulp Fiction says "No, they got the metric system there, they wouldn't know what the fuck a Quarter Pounder is."

The character who says "No, they got the metric system there, they wouldn't know what the fuck a Quarter Pounder is" in Pulp Fiction is Vincent Vega. He utters this line while having a conversation with Jules Winnfield about the differences between America and Europe, specifically referencing the use of the metric system. This dialogue scene adds a touch of humor to the film while highlighting cultural nuances and differences.