To answer this question, the user needs to understand the basic concepts of software testing. Test planning is a crucial stage in software testing, where a comprehensive approach is developed to ensure that the software meets the requirements and is free from defects.

Now, let's go through each option and explain why it is right or wrong:

A. Determining the test approach: This option is correct. Determining the test approach is a major task in test planning. The test approach includes identifying the scope of testing, selecting the right test techniques, and developing a comprehensive test strategy that guides the testing process.

B. Preparing test specifications: This option is incorrect. Preparing test specifications is an important task in test execution, but it is not a major task in test planning. Test specifications are developed based on the test strategy and approach that is defined in the test plan.

C. Evaluating exit criteria and reporting: This option is incorrect. Evaluating exit criteria and reporting are critical tasks in test closure, where the results of the testing are analyzed to determine if the software is ready for release. It is not a major task in test planning.

D. Measuring and analyzing results: This option is incorrect. Measuring and analyzing results are tasks that are performed during the test execution and test closure stages. It is not a major task in test planning.

Therefore, the correct answer is:

The Answer is: A. Determining the test approach.