Explanation:

About La Nina

• La Nina, the “cool phase” of ENSO, is a pattern that describes the unusual cooling of the tropical eastern Pacific.
• La Nina events may last between one and three years, unlike El Nino, which usually lasts no more than a year.
• Both phenomena tend to peak during the Northern Hemisphere winter.

Impact

• Off the west coast of the Americas, upwelling increases, bringing cold, nutrient-rich water to the surface.
• It usually has a positive impact on the fishing industry of western South America.
• It can also lead to a more severe hurricane season.
• Causes the jet stream to move northward and to weaken over the eastern Pacific.
• Causes drought in the South American countries of Peru and Ecuador.
• There are increased temperatures in Western Pacific, Indian Ocean and off the Somalian coast. It also leads to heavy floods in Australia.

Hence option 4th is correct.