Step 1: Find \(k\)
Direction ratios: \(L_1=(-3,2k,2)\), \(L_2=(3k,1,-5)\). Perpendicular: \(-9k+2k-10=0\), so \(k=-\frac{10}{7}\).
Step 2: Directions
\(L_1:(-3,-\frac{20}{7},2)\propto(-21,-20,14)\). \(L_2:(-\frac{30}{7},1,-5)\propto(-30,7,-35)\).
Step 3: Normal
\[ \vec n=(-21,-20,14)\times(-30,7,-35)=(602,-1155,-747) \]
Step 4: Plane
It passes through \((1,2,3)\), which lies on \(L_1\). Constant: \(602-2310-2241=-3949\).
So \(602x-1155y-747z+3949=0\), option (B).
Final Answer:
The plane is \(602x-1155y-747z+3949=0\), option (B).
\[ \boxed{\text{(B)}} \]