Which of the following methods can improve the frame rate in a Unity game?

Optimizing assets and reducing draw calls directly enhances the performance of a Unity game, leading to improved frame rates. When you optimize assets, you reduce the complexity of models and textures, which decreases the amount of data the GPU needs to process. Additionally, when you reduce draw calls, you minimize the number of times the GPU has to switch between different assets during rendering, which is a significant performance bottleneck. By combining similar materials and using techniques like texture atlases, a developer can effectively streamline rendering processes.

In contrast, using more game assets can lead to increased load on the system, as each asset requires memory and processing time. Increasing the number of scripts can also negatively impact performance, as more scripts can lead to more processing overhead, making it harder for the system to maintain a high frame rate. Adding more effects, such as particle systems or post-processing effects, typically demands more computational resources, thus potentially lowering frame rates rather than improving them. Overall, focusing on asset and draw call optimization is the most effective method for enhancing frame rates in Unity.