**Core Concept**
In dentistry, inlay waxes are used for creating dental restorations, and their flow is a crucial property to understand. The flow of inlay wax is determined by the type of wax, temperature, and the angle at which it is poured. Type 1 inlay wax has a specific flow characteristic that is affected by the pouring angle.

**Why the Correct Answer is Right**
When Type 1 inlay wax is poured at a 45-degree angle, the maximum flow occurs due to the balance between the viscous and elastic forces. At this angle, the wax has enough time to flow and fill the mold without losing its shape or becoming too distorted. The flow of Type 1 inlay wax at 45 degrees is optimal for creating accurate dental restorations.

**Why Each Wrong Option is Incorrect**
* **Option A:** Flow at a 90-degree angle is not possible as it would cause the wax to stick to the mold and not flow at all.
* **Option B:** Flow at a 0-degree angle (horizontal) would result in minimal flow due to the wax's tendency to stick to the mold and not spread evenly.
* **Option C:** Flow at a 90-degree angle is not possible as it would cause the wax to stick to the mold and not flow at all.

**Clinical Pearl / High-Yield Fact**
It's essential to note that the flow of inlay wax can be affected by the temperature, and a temperature range of 180°F to 200°F is ideal for pouring Type 1 inlay wax.

**Correct Answer: B. 0.1-0.4mm/min**