Answer: PARALLEL LINES should be coded as "TSHSRRUR RWFUO"
Explanation:
Since we have given that
PARALLEL LINES
As we know that according to alphabets,
P is at 16
A is at 1
R is at 18
L is at 12
E is at 5
N is at 14
S is at 19
And we have given that

So, P becomes :

A becomes

S becomes

L becomes

E becomes

I becomes

N becomes

R becomes

Hence, PARALLEL LINES should be coded as "TSHSRRUR RWFUO"