Right answer is option B, C.
The requirement involves replacing a dependency with an object that has a specific method and ensuring that this method returns an expected result without needing to verify the number of times the method is called. The two test approaches that best describe this scenario are:

B. **Substitution**: This approach involves substituting a real dependency with a controlled replacement during testing. In this case, the database query is substituted with a `Calculator query` method that returns an array.

C. **Stubbing**: This approach involves creating a stub—a controlled replacement for a method or function that provides predefined responses. The `Calculator query` method is stubbed to return a specific array, allowing the test to focus on how the system behaves with the predefined responses.

### Explanation:
- **Substitution** involves replacing the real database dependency with a mock or stub object, which in this case is the `Calculator query` method.
- **Stubbing** refers to the technique of providing predefined responses from the method being replaced, which fits the scenario where the `Calculator query` method returns a specific array.

### Why not the other options?
- **White box** testing involves knowledge of the internal workings of the system. While it may involve stubbing or substitution, it doesn't specifically describe the requirement in this context.
- **Black box** testing focuses on testing the system from an external perspective without knowledge of internal implementation. The described requirement involves a specific method returning an array, which implies some knowledge of the internal workings, making black box less applicable.

Therefore, the two correct test approaches are **Substitution** and **Stubbing**....