Asap! do not answer if you don't know! select all choices that apply. mark each statement that correctly identifies a current theory on why the indus valley civilization declined. choose all answers that are correct. question options: the surrounding land was severely deforested. foreign conquerors forced the people to leave. irrigation made the soil salty and unfit for farming. disease reduced the population. indus valley populations migrated to central asia and africa. for those who are in 7th grade k12 history it is textbook pages 133-135