**Core Concept**
The detection of ductal carcinoma in situ (DCIS) in breast tissue is crucial for early intervention and prevention of progression to invasive cancer. The current gold standard involves imaging and histopathological techniques that provide high sensitivity and specificity for diagnosing DCIS.

**Why the Correct Answer is Right**
The correct answer relies on the principle of high-resolution imaging and histological analysis. Mammography and ultrasound are commonly used imaging modalities, but they may not provide sufficient detail for DCIS detection. **Digital Breast Tomosynthesis (DBT)**, also known as 3D mammography, has been shown to improve detection rates and reduce false positives compared to conventional 2D mammography. The histopathological examination of breast tissue, often in conjunction with DBT findings, confirms the diagnosis of DCIS. This integrated approach provides a comprehensive understanding of the disease.

**Why Each Wrong Option is Incorrect**
**Option A:** Mammography alone may not be sufficient for DCIS detection due to its limitations in resolution and sensitivity.
**Option B:** Ultrasound is not the primary imaging modality for DCIS detection, although it may be used as an adjunct in certain cases.
**Option C:** Magnetic Resonance Imaging (MRI) is not the current gold standard for DCIS detection, although it may be used in specific scenarios, such as high-risk patients.

**Clinical Pearl / High-Yield Fact**
DBT has been shown to reduce the need for additional imaging and biopsies, improving patient outcomes and reducing healthcare costs.

**Correct Answer: C. Digital Breast Tomosynthesis (DBT).**