Universal Containers wants to develop a recruiting app for iOS and Android via the standard...

When developing custom functionality to be surfaced within the standard Salesforce Mobile App, Lightning Web Components (LWC) (Option B) is the recommended approach. LWCs are the modern, high-performance standard for Salesforce development, utilizing modern web standards (ES6+, Web Components) that run natively in the browser.

LWC is preferred over the other options for several reasons:

Performance: LWCs are lightweight and provide a much faster, more responsive user interface than Visualforce (Option D), which is critical for mobile user experience.

Standardization: Since the app will be accessed via the standard Salesforce mobile app, LWCs integrate seamlessly into the mobile navigation, tabs, and action menus.

Customization: LWCs provide full control over the CSS and HTML, allowing the developer to meet the "custom user interface design" requirement while still leveraging the Lightning Data Service for efficient data handling.

Option A (Salesforce SDK) is for building "Custom/Native" standalone apps, not for extending the standard Salesforce app. Option C (Experience Builder) is primarily for external sites (Communities). LWC provides the perfect balance of "custom design" and "native integration" for internal mobile users.