1. What caused the three nuclear reactors in Fukushima, Japan, to melt down? A. a tomado B. a tsunami C. warfare D. human error

## Step 1<br />The problem is asking for the cause of the meltdown of the three nuclear reactors in Fukushima, Japan. The options provided are a tornado, a tsunami, warfare, and human error.<br />## Step 2<br />The correct answer is B, a tsunami. The meltdown occurred in March 2011 after a massive 9.0-magnitude earthquake off the coast of Japan triggered a tsunami. The tsunami caused a loss of power and cooling to the reactors, leading to the meltdown.<br />## Step 3<br />The other options, a tornado, warfare, and human error, are not the direct causes of the meltdown. While human error played a role in the disaster, the immediate cause was the natural disaster of the tsunami.