It was true that
P : the pet dog
Q : would never sleep anywhere
R : we once had
S : except on the sofa

The Proper sequence should be:

A. PQSR

B. PRQS

C. RPQS

D. SPQR

Answer: Option B

Solution(By Examveda Team)

It was true that the pet dog we once had would never sleep anywhere except on the sofa.