Explanation
The correct syntax for looping through a series of child components which are tiles is option A. Option A uses the for:each directive to iterate over a collection of items and render a template block for each item. The for:each directive requires an expression that evaluates to an array or an iterable object and an item alias that represents the current item in the iteration. The item alias can be used to access the item's properties or pass them to child components. In option A, the expression is appTiles, which is an array of objects that represent app tiles, and the item alias is appTile, which represents the current app tile object in the iteration. The appTile object's properties, such as name, description, and icon, are passed to the app-tile child component using attributes. Option B is incorrect because it uses an invalid syntax for the for:each directive. The for:each directive requires a colon (:) after the for keyword, not an equal sign (=). Option C is incorrect because it uses an invalid syntax for the for:each directive. The for:each directive requires an item alias that represents the current item in the iteration, not a key alias that represents the current index in theiteration. Option D is incorrect because it uses an invalid syntax for the template tag. The template tag requires a closing tag (</template>), not a self-closing tag (<template/>). Salesforce References: Lightning Web Components Developer Guide: Iterate Over a Collection, Lightning Web Components Developer Guide: Template Syntax