The equation of the plane containing the $\frac{x – α}{l}=\frac{y – β}{m}=\frac{z – γ}{n}$ line is $a(x – α) + b(y – β) + c(z – γ) = 0$, where al + bm + cn is equal to

0

Since the given straight line lies in the plane, it will be perpendicular to the normal to the given plane.

Since direction cosines of the given straight line are l, m, n and direction ratios of normal to the plane are a, b, c, al + bm + cn = 0.

Hence (D) is the correct answer.