A few weeks ago , my family and I went on a little family vacation for a couple of days . I accidentally left the front door unlocked . No one panicked , though , because we live in a relatively safe neighborhood and our neighbors all know each other .

Question: What may be the reason they usually lock the door even though they live in a safe neighborhood ?
Answer: They have pets that might get out .There have been break ins lately .It sets their mind at ease .None of the above choices .