The correct option is A √143
We know
d=|(→p−→a)×→c||→c|
Given: L:→r=2^i+^j+3^k+λ(^i+^j+^k),→p=^i+2^j+^k
Comparing with →r=→a+λ→c, we have (→a)=2^i+^j+3^k and →c=^i+^j+^k
Here, (→p−→a)=−^i+^j−2^k
Now, (→p−→a)×→c=∣∣
∣
∣∣^i^j^k−11−2111∣∣
∣
∣∣=3^i−^j−2^k
⇒|→c|=√3
d=|(→p−→a)×→c||→c|=|3^i−^j−2^k|√3
Thus, d=√143 units