In 2 BC, a change in weather conditions caused the Arabian Sea to suddenly rise. This sea connected to the Indus River. The Harappans were used to the yearly flooding of the Indus River. In fact, they depended on it for fertile farming soil it created. They also built their houses on high platforms to protect themselves. However, the sudden increase in the sea level worsened the yearly flooding of the Indus River. The high platforms were all flooded by the overflowing water. What theory about the decline of the Harappan civilization does this passage support?

The passage supports the theory. It suggests that the Indus valley civilization declined because of .