If the straighat lines `x=1+s,y=-3-lamdas,z=1+lamdas and x=t/2,y=1+t,z=2-t` with parameters s and t respectively, are coplanar, then `lamda` equals (A) `-1/2` (B) `-1` (C) `-2` (D) `0`

Explanation

The given lines `(x+1)/(1)=(y-3)/(-lamda)=(z-1)/(lamda)=s`
`and " "(x-0)/(1//2)=(y-1)/(1)=(y-2)/(-1)=t`
are coplanar if `|{:(0+1,,1-3,,2-1),(1,,-lamda,,lamda),(1//2,,1,,-1):}|=0 or |{:(1,,-2,,1),(1,,-lamda,,lamda),(1//2,,1,,-1):}|=0`
or `" "1(lamda-lamda)+2(-1-(lamda)/(2))+1(1+(lamda)/(2))=0`
or `" "lamda=-2`