Step 1: Understanding the Concept:
Sensory thresholds are used to measure perception.
Different types of thresholds exist.
Step 2: Key Formula or Approach:
No specific formula.
Need to know the types of sensory thresholds.
Step 3: Detailed Explanation:
Recognition threshold is the concentration at which a specific taste can first be identified.
Detection threshold is the minimum concentration at which a stimulus can be detected.
Absolute threshold is the minimum intensity of a stimulus that can be detected.
Sensitivity threshold is not a standard term.
Thus, recognition threshold is the correct answer.
Step 4: Final Answer:
The concentration at which a specific taste can first be identified is the recognition threshold.
Hence, the correct option is (A).