Which one of the following is a test for concrete consistency?

The test for concrete consistency being the slump test is crucial for evaluating how workable a batch of concrete is. The slump test measures the flow or "slump" of fresh concrete by determining how much it settles when placed in a cone-shaped mold. This gives a quick and direct indication of the water-cement ratio and overall consistency, which directly impacts the strength and durability of the concrete once it has cured.

In contrast, the other tests mentioned do not serve the same purpose. A load test evaluates how much weight concrete can support without failing, focusing on its structural capacity. Compression tests measure the concrete's compressive strength after it has hardened, indicating how well it can withstand loads in a structural application. Tensile tests assess the material's resistance to tension, which is typically not a primary concern for concrete because it is inherently weak in tension. Therefore, the slump test is uniquely suited to assess the workability and consistency of fresh concrete, making it the correct answer.