The best answer is
A) JSON is quicker to read and write.
JSON (JavaScript Object Notation) is a lightweight data-interchange format that is based on the JavaScript programming language and easy to understand and generate. JSON uses a simple syntax that consists of name-value pairs and arrays, and does not require any end tags or attributes. JSON is quicker to read and write than XML (Extensible Markup Language), which is a markup language that uses a tag structure to represent data items. XML has a more complex and verbose syntax that requires end tags, attributes, and namespaces123

For a dashboard that aims to tell a story about sales and the sales customer ratio, a column chart is an effective choice. Column charts are particularly useful for showing data changes over a period of time or for illustrating comparisons among items. In this case, a column chart can clearly display the sales figures for each site, allowing for easy comparison across different sites. Additionally, it can be used to represent the sales customer ratio by showing the proportion of sales per customer, which can provide insights into customer behavior and sales effectiveness.
* Line charts are best suited for displaying data trends over time, rather than for comparing individual categories.
* Pie charts could show the proportion of sales for each site, but they are not as effective as column charts for comparing multiple categories.
* Scatter charts are used to show the relationship between two variables, which is not the focus in this scenario.
References:
* Effective Use of Column Charts1
* Choosing the Right Chart for Your Data2
* Sales Dashboards: Examples & Templates3

Explanation
Systematic sampling is a type of sampling where the sample is selected by following a fixed interval. For example, every 10th person in a list is chosen for the sample. In the image, the sample is selected by choosing every 3rd person in the line, starting from person number 1. This is an example of systematic sampling.
References: Types of Sampling Techniques in Data Analytics You Should Know, Sampling Methods | Types, Techniques & Examples - Scribbr