Final answer:
The best time frame to analyze the sample to ensure accurate results is within 30 minutes to 1 hour.
Step-by-step explanation:
The best time frame to analyze the sample to ensure accurate results is d. Within 30 minutes to 1 hour. This time frame allows for minimal changes or degradation in the sample, ensuring the accuracy of the results. Analyzing the sample too soon (c. 2 to 3 hours) or too late (a. 4 to 6 hours) could lead to inaccurate results.