<div  v-for="subject in subjects" v-bind:class="classObject" >{{subject.question}}             <input type="radio" id="a" value="a" name="forradio" v-on:click="check_question">             <label for="a">{{subject.answer_a}}</label>             <input type="radio" id="b" value="b"  name="forradio"  v-on:click="check_question">             <label for="b">{{subject.answer_b}}</label>             <input type="radio" id="c" value="c" name="forradio"  v-on:click="check_question">             <label for="c">{{subject.answer_c}}</label>             <input type="radio" id="d" value="d" name="forradio"  v-on:click="check_question">             <label for="d">{{subject.answer_d}}</label>             </div>這樣不行，會導致所有單選只能選擇一個