But the first time we left Mat in the house unattended , he chewed up one set , and Ginger finished the other set off by crawling through them and breaking them . We ' ve replaced one , but in order to avoid the new blinds from meeting the same fate as the old ones , they are permanently tied off at the halfway mark . Which means the bottom half of our 6 ft long windows are completely exposed .

Question: Why did the writer tie off their blinds at the halfway mark ?
Answer: None of the above choices .They wanted to have the bottom half of their windows exposed .Because their pets destroyed the blinds they had so that was the best solution they could come up with .Because they wanted to replace them .