Answer:
Options A, B and D except C
Explanation:
From the passage, the most missing children are returned home alive.
Let put this into math;
i,e 98% of the missing children are returned home or located.
The remaining 2% explains there are not found, that is why they are not returned home.
In conclusion. this 2% of missing children not returned or located are either
1. Killed and there bodies are not found , that is why they couldn't return them home.
2. Taken from the country , which explains that they are not found within the area there were missing
3. Sold in slavery, here slavery without a trace is possible that is why they are not found.
The reason option C is not selected is because "runaways from institutions" children are not missing children, there is a possibility there are children that ran just from institutions but not missing at home. so therefore, options A, B and D explains why 2% of the missing children are not returned or located.