**Core Concept**
Root end preparation is a crucial step in endodontic therapy, especially in teeth with short roots. The goal is to create a well-sealed and anatomically correct preparation to ensure the success of the root canal treatment.

**Why the Correct Answer is Right**
In teeth with short roots, a more conservative approach is necessary to avoid compromising the structural integrity of the tooth. The **Crown Down** technique is a common method used for root end preparation in such cases. This technique involves preparing the root canal from the coronal aspect, working down towards the apical foramen, to minimize the risk of root fracture. The apical foramen is preserved, and the preparation is extended to create a well-sealed and anatomically correct root end.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it does not specify any particular technique or approach for root end preparation in teeth with short roots.
* **Option B:** This is not a recognized technique for root end preparation in endodontics.
* **Option D:** This option is incorrect as it does not provide any relevant information regarding root end preparation in teeth with short roots.

**Clinical Pearl / High-Yield Fact**
The Crown Down technique is a conservative approach that helps minimize the risk of root fracture in teeth with short roots. It is essential to preserve the apical foramen and create a well-sealed and anatomically correct root end to ensure the success of the root canal treatment.

**Correct Answer: C. Crown Down technique**