The main emphasis in a system flow chart is: A. data flow. B. technical details. C. exploration of operations. D. none of these.

In understanding system flow charts, it's important to note what their main focus is. A system flow chart visually represents the flow of data and processing within a system, typically emphasizing how information moves from one step to another.

1. Data Flow (Option A): This option suggests that the primary focus of a system flow chart is on how data travels through different processes and decisions.

2. Technical Details (Option B): This would imply that the chart's main purpose is to share intricate technical specifics of the system.

3. Exploration of Operations (Option C): This involves understanding the various operations within the system, but it doesn't encapsulate the primary focus of a flow chart.

4. None of These (Option D): This implies that none of the described focuses align with the main emphasis of a system flow chart.

Analysis:

The essence of a system flow chart lies predominantly in illustrating the movement of data, which anchors the entire process. While technical details and operations can be represented, they are secondary to the primary goal of mapping out data flow.

Final Answer:

A. data flow.