The question was "What is your husband's favorite South American country?"
The first wife answered Brazil.
The second wife was a bit puzzled as to what the term "South American" meant. She answered "New Mexico." The MC explained to her that that was a U.S. state, not a South American country. still confused as to what this strange adjective "South American" meant, she answered "Mexico." The third wife was sure of her answer. She wasn't as confused as wife number two and showed it. when it came time to give her answer, she answered very confidently "I know what my husband's favorite South American country is: it's Africa!" The MC allowed it.
The fourth wife answered "Mexico" as well. One out of four ain't bad.
The only husband to give the same answer as his wife was the fourth, who answered "Mexico."