次のベクトルと行列の演算結果として、正しいものを選んでください
$$
{LARGE [
left(
begin{array}{ccc}
3 \
4
end{array}
right)
left(
begin{array}{ccc}
1 & 2
end{array}
right)
] }
$$
[選択肢]
1. $$1$$
2. $${LARGE [
bm{A} = left(
begin{array}{ccc}
3 & 6 \
4 & 8
end{array}
right) ] } $$
3. $${LARGE [
bm{A} = left(
begin{array}{ccc}
3 \
8
end{array}
right) ] } $$