Chọn phương án A.

Giả sử \(D(x;0;0)\in Ox\). Ta có

• \(\overrightarrow{AD}=(x-3;4;0)\Rightarrow AD=\sqrt{(x-3)^2+4^2}\)
• \(\overrightarrow{BC}=(4;0;-3)\Rightarrow AD=\sqrt{4^2+(-3)^2}=5\)

\(\begin{aligned}
AD=BC\Leftrightarrow&\sqrt{(x-3)^2+4^2}=5\\
\Leftrightarrow&(x-3)^2+4^2=5^2\\
\Leftrightarrow&(x-3)^2=9\\
\Leftrightarrow&\left[\begin{array}{l}x-3=3\\ x-3=-3\end{array}\right.\\
\Leftrightarrow&\left[\begin{array}{l}x=6\\ x=0\end{array}\right.\\
\Leftrightarrow&\left[\begin{array}{l}D\left(6;0;0\right)\\ D\left(0;0;0\right).\end{array}\right.
\end{aligned}\)