The question states that the DataPrettyPrint module has one default export, the function printDate(). According to the ECMAScript (ES6) module specification, which Lightning Web Components use, a default export is imported without curly braces {}. The developer can assign any valid name to the imported function. Option B correctly imports the default function, assigns it the local name myPrintDate, and then invokes it. This syntax is the standard and correct way to handle default imports.

A: This syntax, using curly braces {}, is for importing named exports. The question specifies a default export, making this syntax incorrect.

C: While the import statement itself is syntactically correct for a default export, the function call DataPrettyPrint.printDate() is wrong. The default export is assigned directly to the printDate identifier, not as a property of an object named after the module.

D: This syntax import { ... as ... } is used for importing and renaming a named export. It is not the correct syntax for a default export.

1. Salesforce Lightning Web Components Dev Guide: In the "Share JavaScript Code" section, under "JavaScript Modules," the documentation explicitly differentiates between named and default exports. It states, "To import the default export, don’t use curly braces." It provides an example: import util from 'c/utils';, which directly matches the syntax used in the correct answer.

Reference: Lightning Web Components Dev Guide > Developer Tools > Share JavaScript Code > JavaScript Modules.

2. MDN Web Docs (Mozilla): The official Mozilla documentation for JavaScript provides a definitive guide on import and export syntax.

For import, it specifies the syntax for importing defaults as: import defaultExport from "module-name";. This confirms that a custom name can be assigned to the default export without using curly braces.

Reference: MDN Web Docs, import statement, "Importing defaults" section.

3. Exploring ES6 (by Dr. Axel Rauschmayer): This peer-reviewed book on JavaScript features is a highly respected academic resource.

In Chapter 17, "Modules," Section 17.3.2, "Default exports (one per module)," it explains that a default export is imported with the syntax import myIdentifier from 'src/mylib';. This directly supports the structure of the correct answer.

Reference: Rauschmayer, A. (2015). Exploring ES6. Chapter 17, Section 17.3.2.