choice_radio

{
    "type": "choice_radio",              // string, must be "choice_radio"
    "name": "el4",                       // string, not empty, unique
    "required": false,                   // boolean
    "label": "Label",                    // string, not empty
    "microcopy": "",                     // string
    "other_option": false,               // boolean
    "options": [ /* element options */ ] // array, must have at least one option
}