To move a block from one container to another, the developer needs to use the layout instruction with the element attribute specifying the name of the block and the destination attribute specifying the name of the container. The after attribute can be used to position the block relative to other blocks in the same container. The value “-” means that the block will be placed after all other blocks, i.e., as the last child. The value “last-child” is not valid for the after attribute and will not work. The element and destination attributes should use the names of the blocks and containers, not their aliases or classes. References: [Layout instructions], [Move an element]

Option C is the correct way to implement the viewport button icon. The image node specifies the path to the .svg file relative to the web/css directory of the module. Option A is incorrect because there is no icon node in the viewport configuration data. Option B is incorrect because there is no button-image node in the viewport configuration data. Option D is incorrect because the image node value should not include the web/css part of the path.