**Core Concept**
Obsessive-compulsive disorder (OCD) is a psychiatric condition characterized by recurring, intrusive thoughts (obsessions) and repetitive behaviors (compulsions) that an individual feels compelled to perform. These behaviors are aimed at reducing anxiety, but they often interfere with daily life.

**Why the Correct Answer is Right**
The features listed - fear of contamination, counting behaviors, and having to check and recheck - are classic examples of compulsions in OCD. Individuals with OCD often exhibit excessive cleaning or washing behaviors due to fear of contamination, engage in ritualistic counting or arranging activities, and repeatedly check things like locks or appliances to alleviate anxiety. This is because the brain's limbic system, particularly the amygdala and anterior cingulate cortex, is overactive, leading to an exaggerated fear response and the urge to perform compulsive behaviors.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the question as it does not describe a feature of OCD.
* **Option B:** While anxiety disorders share some similarities with OCD, the specific behaviors described in the question are characteristic of OCD rather than a broader anxiety disorder.
* **Option C:** This option is not directly related to the question, as it does not describe a feature of OCD.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that OCD is a spectrum disorder, and individuals may exhibit a range of symptoms. The presence of just one or two of the characteristic features listed in the question can still indicate OCD. A thorough psychiatric evaluation is necessary to diagnose OCD accurately.

**Correct Answer: D. Obsessive-compulsive disorder.**