Normalizing the variables means scaling them to a common range, such as 0 to 1 or -1 to 1, so that they have the same weight in the score calculation. Recoding the variables means changing their values or categories, which would alter their meaning and distribution. Calculating the percentiles of the variables means ranking them relative to each other, which would not account for their actual magnitudes. Calculating the standard deviations of the variables means measuring their variability, which would not make them comparable.
References: CompTIA Data+ Certification Exam Objectives, page 10

A dashboard is a graphical display that summarizes and presents key performance indicators (KPIs) and metrics for a business or a project. A dashboard should be clear, concise, and easy to understand. To develop a dashboard, one of the best practices is to create a wireframe or a mockup first. A wireframe or a mockup is a low-fidelity sketch or prototype of the dashboard layout and design, which helps to define the scope, requirements, and functionality of the dashboard. Creating a wireframe or a mockup can help to save time and resources, as well as to get feedback from stakeholders and users before deploying the dashboard to production. Therefore, the correct answer is A. Reference: [Dashboard Design Best Practices: 4 Key Principles | Toptal], [How to Create an Effective Dashboard (with Examples) | Tableau]