data: () => ({
items: [...Array(10)].map((n, i) => `item ${i}`),
selected: Array(4).fill(null),
}),
<select v-for="(s, i) in selected" v-model="selected[i]">
<option
v-for="n in items"
v-text="n"
:disabled="selected.includes(n)"
></option>
</select>