Gap analysis is a core business analysis technique used to compare the current state ('as-is') with the desired future state ('to-be'). The process fundamentally involves three key stages. First, it is essential to thoroughly investigate and understand the existing situation (A). Next, this current state is compared against the defined target or desired situation to identify the differences, known as 'gaps' (B). Finally, once the gaps are clearly identified, the analysis proceeds to consider the possible high-level actions or changes required to bridge these gaps and transition from the current to the desired state (C). These three activities represent the essence of the gap analysis process.

D. Defining the solutions to close the gaps: This is a subsequent, more detailed design activity that follows the initial analysis of identifying gaps and considering high-level actions.

E. Deliver the solution to close the gaps: Delivering the solution is part of the project implementation or change delivery lifecycle, which occurs well after the gap analysis is complete.

1. Paul, D., Cadle, J., & Yeates, D. (2020). Business Analysis (4th ed.). BCS, The Chartered Institute for IT.

Chapter 10, Section 10.2, 'The gap analysis process': This section explicitly outlines the process: "The first step is to investigate and describe the existing business situation... The second step is to define the target business situation... The third step is to compare the two situations in order to identify the gaps... The final step is to identify the actions required to bridge the gaps." This directly supports options A, B, and C as the core steps.

2. The University of Texas at Austin, IT Service Management Courseware.

Document: 'Gap Analysis Template and Instructions': The instructions for performing a gap analysis state the key steps as: "1. Identify the Current State... 2. Identify the Future State... 3. Identify the Gaps... 4. Identify Actions/Projects to Close the Gaps." This aligns with understanding the existing situation (A), comparing it to the desired state (B), and considering actions (C).

3. Kaur, A., & Kautish, S. (2019). A roadmap from as-is to to-be state in business process management: a systematic literature review. International Journal of Business Process Integration and Management, 9(4), 336-353.

Section 3, 'Methodology': The paper describes the standard methodology for moving from an 'as-is' to a 'to-be' state, which is the foundation of gap analysis. It emphasizes the phases of "As-Is process modeling," "As-Is process analysis," "To-Be process design," and "process implementation." The first three phases correspond to understanding the current state, comparing it with a desired state, and considering actions/redesign, supporting the correctness of A, B, and C as analysis activities. DOI: https://doi.org/10.1504/IJBPIM.2019.103998