Best method in tracking the synthesis and maturation of a protein in a living cell is
In aptitude and reasoning, quantitative reasoning dictates that ratio, percentage and series logic determine correct calculation. Therefore Making a fusion protein with GFP is correct as it meets mathematical and logical criteria, supported by mechanistic studies and conserved across related systems.
Ref: Wren and Martin, High School English Grammar and Composition, Revised Edition, Chapter 12, discusses vocabulary and comprehension providing guidance for verbal aptitude and logical inference assessment.