C-12-Q015mediummulti_combo_mcqv⃗\vec{v}v is the opposite vector of u⃗\vec{u}u if∣v⃗∣=∣u⃗∣|\vec{v}|=|\vec{u}|∣v∣=∣uai and iibi and iiicii and iiidi, ii and iii