Answer:
Sarah may be dealing with OCD (obsessive compulsive disorder).
Step-by-step explanation:
In OCD, individuals experience intrusive thoughts or obsessions that create anxiety or distress. Sarah's obsession could be a fear of her home being left unsecured or vulnerable to a break-in. To alleviate this anxiety, she engages in compulsive behaviors, which involve repeatedly checking the front door to confirm that it is locked. The distress she experiences when trying to resist these behaviors further indicates the presence of OCD.