Concept:The angle between two lines is obtained from the dot product of their direction vectors.Explanation:For the first line, take 2x−1=42y+3=λ and z=−2.This gives x=1+2λ, y=2λ−23, and z=−2.So the direction ratios of the first line are (2,2,0), which simplify to (1,1,0).For the second line, take x=1 and 2y−1=2z+1=μ.This gives y=1+2μ and z=−1+2μ.So the direction ratios of the second line are (0,2,2), which simplify to (0,1,1).Let a=(1,1,0) and b=(0,1,1).Using cosθ=∣a∣∣b∣∣a⋅b∣:a⋅b=(1)(0)+(1)(1)+(0)(1)=1.∣a∣=12+12+02=2 and ∣b∣=02+12+12=2.Thus, cosθ=2⋅21=21.Hence, θ=3π.Answer:θ=3π, which is Option B.