The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
Forthelinestobeparallela1a2=b1b2≠c1c2.Theequationsarex+y−4=0and2x+ky−3=0.Herea1=1,b1=1andc1=−4.a2=2,b2=kandc2=−3.∴a1a2=12,b1b2=1k,c1c2=−4−3=43.So1k=12⇒k=2Sotheassertioniscorrect.Butwhena1a2≠b1b2,theequationhasauniquesolution.So,thesystemisconsistent.Sothisreasonistrue.∴Thereasondoesnotexplaintheassertioncorrectly.Ans−OptionB.