The exit criterion EX1 states, "100% of tests of priority 1 have been executed and passed." By analyzing the provided table, we can identify a total of seven test cases with Priority 1: TC-001, TC-002, TC-003, TC-004, TC-005, TC-006, and TC-007.

The scenario specifies that three of these Priority 1 test cases (TC-001, TC-002, and TC-007) have already been executed and passed. To satisfy the 100% completion requirement of EX1, the remaining Priority 1 test cases must also be successfully executed. The remaining test cases are TC-003, TC-004, TC-005, and TC-006, which amounts to a minimum of 4 test cases.

B. 5: This is an incorrect calculation of the remaining Priority 1 test cases required to meet the exit criterion.

C. 6: This is an incorrect calculation of the remaining Priority 1 test cases required to meet the exit criterion.

D. 7: This represents the total number of Priority 1 test cases, not the number remaining to be executed to meet the criterion.

1. ISTQB® Foundation Level Syllabus (Version 2018 V3.1.1): Section 5.2.4, "Test Plan," defines Exit Criteria as "The set of generic and specific conditions... for permitting a process to be officially completed." The question requires applying this principle by evaluating progress against a specific exit criterion (EX1). The calculation involves determining the remaining work to satisfy the condition of "100% of tests of priority 1 have been executed and passed."

2. Kaner, C., Falk, J., & Nguyen, H. Q. (1999). Testing Computer Software. John Wiley & Sons. In Chapter 8, "Test Planning," the concept of "Release Criteria" or "Exit Criteria" is discussed. The text emphasizes that these criteria are specific, measurable conditions that must be met, such as "all high-priority tests must pass." The problem presented is a direct application of this test management principle.

3. MIT OpenCourseWare, 6.170 Software Studio, Spring 2013: Lecture 10, "Testing," discusses the components of a test plan, including test completion criteria. These criteria define when testing is considered finished, for example, when a certain percentage of test cases have passed. The question assesses the ability to calculate progress towards such a pre-defined completion criterion. (Available at: https://ocw.mit.edu/courses/6-170-software-studio-spring-2013/)