To override the parent theme styles, the developer needs to change the web/css/source/_extend.less file in the child theme. This file is used to import and extend the parent theme styles without modifying the original files. The developer can use the @import directive to import the parent theme styles and then use the .lib-css() mixin to override the CSS properties. For example:

@import ‘source/_extend.less’; // Import parent theme styles .lib-css(color, red); // Override color property

The web/css/source/_extends.less and web/css/source/_theme.less files are not valid and will not work, as they do not follow the theme structure or the naming convention. References: [Theme inheritance], [Extend parent theme styles]

To remove the default Wishlist and Compare Products blocks on a category page with layered navigation, the developer should place the modification in the app/design/frontend/Vendor/Theme/Magento_LayeredNavigation/layout/catalog_category_view_type_layered.xml file. This file is specific to the category pages with layered navigation and will override the default layout file from the Magento_LayeredNavigation module. The modification should use the tag with the name attribute specifying the name of the block and the remove attribute set to true. For example:

The app/design/frontend/Vendor/Theme/Magento_LayeredNavigation/layout/override/catalog_category_view_type_layered.xml file is not valid and will not work, as it is not a valid override path. The app/design/frontend/Vendor/Theme/Magento_Catalog/layout/catalog_category_view.xml file is not specific to the category pages with layered navigation and will affect all category pages. References: [Layout override], [Remove an element]

Option A is the correct way to initialize a JS component via Layout XML in a custom reference block. The x-magento-init tag is used to specify the component name and the options. Option B is incorrect because it uses the data-mage-init attribute, which is only valid for HTML elements. Option C is incorrect because it uses the x-magento-component tag, which is deprecated and should not be used.