**Core Concept**
Unfilled methyl methacrylate is a type of dental restorative material, commonly used in dental prosthetics and repairs. Its unique properties make it suitable for various dental applications.

**Why the Correct Answer is Right**
The correct answer is that unfilled methyl methacrylate can be finished smoothly. This is due to its viscosity, which allows for easy shaping and polishing without the need for additional fillers. The smooth finish is essential for creating a comfortable and aesthetically pleasing oral environment. Additionally, the material's ability to be finished smoothly enables dentists to create a strong bond between the restoration and the surrounding tooth structure.

**Why Each Wrong Option is Incorrect**
**Option A:** It can be finished smoothly - This option is already the correct answer, so it will not be discussed further.
**Option B:** It has a low degree of flow - Unfilled methyl methacrylate actually has a relatively high degree of flow, which can make it challenging to handle and shape.
**Option C:** It's non-irritation to pulp - While unfilled methyl methacrylate is generally considered biocompatible, it is not specifically known for its non-irritation properties to pulp.
**Option D:** It's wear resistant is high - Unfilled methyl methacrylate has limited wear resistance compared to other dental materials, such as composite resins.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that unfilled methyl methacrylate is often used as a temporary or provisional material in dental restorations. Its smooth finish and ease of handling make it an ideal choice for these applications.

**Correct Answer:**
✓ Correct Answer: A. It can be finished smoothly