And then there is the third alternative: 3. "Before the negotiations were finalized, Bill Clinton came into office in the U.S. and Kim Campbell in Canada, and before the agreement became law, Jean Chrétien had taken office in Canada."
Of course, the third alternative, which took about 30 seconds to research, was beyond your comprehension.
At least you've finally learned, a mere 15+ years after the law was passed, that is was President Bill Clinton, not President Ronald Reagan, that signed the greenest trade agreement ever written into law. Your mountain of ignorance is one grain of sand smaller.
Dear God. Now you are using Wikipedia. Game over.