Correct

十万八千里

/ shí wàn bā qiān lǐ / 
Strokes

Definition

light-years (apart)/a million miles (apart)/(i.e. indicates a huge difference or a huge distance)

Example

Definition

distance of one hundred and eight thousand li ―poles apart; as far as can be

1
Xiānggé
相隔
shíwànbāqiānlǐ
十万八千里

be poles apart

2
Lítí
离题
shíwànbāqiānlǐ
十万八千里

be miles away from the subject; be completely off the point