<input type="checkbox" value="a" checked style="margin-top:17px;" v-model="a" />A
<input type="checkbox" value="b" checked style="margin-left:3.6%;" v-model="b" />B
<input type="checkbox" value="c" checked style="margin-left:3.6%;" v-model="c" />C
<input type="checkbox" value="d" checked style="margin-left:3.6%;" v-model="d" />D
<input type="checkbox" value="b" checked style="margin-left:3.6%;" v-model="b" />B
<input type="checkbox" value="c" checked style="margin-left:3.6%;" v-model="c" />C
<input type="checkbox" value="d" checked style="margin-left:3.6%;" v-model="d" />D