[Vuejs]-Identify selected option using v-model in select box

You should take a look at the docs and how they do databinding with select.

https://jsfiddle.net/s3x096u3/1/

<select v-model="selected">
    <option v-for="item in vals" :value="item.value" :key="item.value">{{item.value}}</option>
  </select>

With regards to your code, a select attribute on an option element doesn’t do anything.