The Parse Variable pattern operation allows you to extract information from the output of a previous operation and save it in a variable. You can choose from different parsing methods, such as JSON File, XML File, Regular Expression, or Custom Script. To have two different parsing methods to populate variables, you need to use two different steps, each with a different Define Parsing selection. For example, you can use one step to parse a JSON file and another step to parse an XML file. You cannot use two different parsing methods on the same step, as the Define Parsing selection is unique for each step.
References:
* Parse command output: This article explains how to use the Parse command output operation and the different parsing methods available.
* Pattern Designer: Parse Variable - JSON File gives error: This article provides a troubleshooting tip for using the JSON File parsing method.
* Examples of EVAL scripts used in Discovery patterns: This article provides some examples of custom scripts that can be used for the Custom Script parsing method.

* A is true because the target table $cmdb_ci_web_server is a ServiceNow CMDB table that stores information about web servers1.
* B is true because the merge table operation is typically used for application patterns, which are horizontal patterns that discover applications and their dependencies. The condition on the process.executablePath variable suggests that the operation is looking for a specific application (mongoose) running on the web servers.
* D is true because the merge table operation requires at least one matching field value between the two source tables1. In this case, the process.executablePath variable is the matching field, and it must contain "mongoose" for the operation to run.
References:
* 1: Merge tables - Product Documentation: San Diego - Now Support Portal
* 3: Product Documentation | ServiceNow
* [4]: Discovery Patterns - Product Documentation: San Diego - Now Support Portal