**Core Concept**
Suture materials can be broadly categorized into two types: natural and synthetic. Natural sutures are derived from biological sources, such as catgut (made from the intestines of animals), while synthetic sutures are made from man-made materials like nylon or polypropylene.

**Why the Correct Answer is Right**
The correct answer, **B. Synthetic sutures**, refers to the fact that 10-0 sutures are typically made from synthetic materials. These sutures are designed to be finer and more precise than larger sutures, allowing for delicate tissue handling in surgical procedures. Synthetic sutures, such as nylon or polypropylene, are chosen for their strength, durability, and resistance to infection.

**Why Each Wrong Option is Incorrect**
**Option A:** Thicker than 1-0 sutures - This statement is incorrect because 10-0 sutures are actually finer than 1-0 sutures, not thicker. The number preceding the zero in a suture size indicates the diameter of the suture, with smaller numbers corresponding to finer sutures.
**Option C:** Diameter is 0.9 mm - This statement is incorrect because the diameter of a 10-0 suture varies depending on the material, but it is generally in the range of 0.1-0.2 mm, not 0.9 mm.
**Option D:** Stronger than 1-0 - This statement is incorrect because while 10-0 sutures are strong for their size, they are not necessarily stronger than 1-0 sutures. The strength of a suture is related to its material and construction, not just its size.

**Clinical Pearl / High-Yield Fact**
When choosing sutures, it's essential to consider the specific requirements of the surgical procedure, including the type of tissue being repaired, the desired strength and durability, and the potential for infection.

**✓ Correct Answer: B. Synthetic sutures**