Answer
Vectors $v_2$ and $v_3$ are orthogonal.
Work Step by Step
When the dot product between two vectors is $0$, then they are perpendicular or orthogonal.
We calculate the dot product between vectors $2$ and $3$:
$v_2 \cdot v_3=(-3i-6j)(-8i+4j) \\=(-3)(-8)+(-6)(4)\\=24 -24 \\=0$
We get $0$, which implies that $v_2$ and $v_3$ are orthogonal. Multiplying the other vectors does not produce a zero dot product.
