The app builder should use a custom button and Flow to achieve the desired result. A custom button is a button that can invoke custom logic or actions when clicked by a user. A Flow is a type of automation tool that can guide users through a series of screens and perform actions based on user input. In this case, the app builder can create a custom button on the Account object that launches a Flow when clicked by a user. The Flow can display a popup window with questions for the user to answer and populate additional fields on the Account record based on the user input4. Option A, B, and C are not tools that can achieve this result.