**Core Concept**
Exposure therapy is a type of behavioral therapy used to treat anxiety disorders, including contamination phobia (also known as mysophobia). This technique involves gradual exposure to the feared object or situation to reduce anxiety and promote habituation.

**Why the Correct Answer is Right**
The procedure described is a form of exposure therapy known as "guided participation" or "participant modeling." The therapist's calm and gentle demeanor helps the patient feel more comfortable with the exposure, while the repeated practice of touching objects that the therapist has touched helps the patient gradually become desensitized to the feared stimuli. This technique is often used to treat contamination phobia by exposing the patient to the feared object (e.g., a door handle) in a controlled and gradual manner.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not a specific type of therapy, making it a vague and incorrect choice.
**Option B:** Systematic desensitization is another type of exposure therapy, but it typically involves a hierarchy of feared stimuli, whereas the described procedure is more focused on direct exposure.

**Clinical Pearl / High-Yield Fact**
Exposure therapy is a highly effective treatment for anxiety disorders, including contamination phobia, when implemented correctly. It is essential to tailor the exposure hierarchy to the individual patient's needs and to provide a supportive and non-judgmental therapeutic environment.

**Correct Answer:** B.