**Core Concept**
The question tests the understanding of **monoclonal antibodies** and their classification, specifically focusing on **humanized antibodies**. Humanized antibodies are engineered to have a **human** immune response, reducing **immunogenicity**.

**Why the Correct Answer is Right**
A humanized antibody is created by transferring the **complementarity-determining regions (CDRs)** from a **murine** antibody to a **human** antibody framework. This process retains the **antigen-binding specificity** of the original murine antibody while reducing its **immunogenicity** in humans.

**Why Each Wrong Option is Incorrect**
**Option A:** Is incorrect because it does not specify a humanized antibody.
**Option B:** Is incorrect as it is not a commonly recognized humanized antibody.
**Option C:** Is incorrect because it is not identified as the correct answer.

**Clinical Pearl / High-Yield Fact**
Humanized antibodies, such as **Trastuzumab**, are used to treat various conditions, including **breast cancer**. Remembering the mechanism of action and the engineering process behind these antibodies is crucial.

**Correct Answer:** D. Trastuzumab