Read the following context and choose the best option to answer the question.
Context: 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 ?
Options: 
A. They have pets that might get out .
B. There have been break ins lately .
C. It sets their mind at ease .
D. None of the above choices .


C