If neither I nor II follows
From the statements, Rats ⊂ Cats ⊂ Dogs. Hence, all Rats are also Dogs.
Therefore, both conclusions—some Dogs are Rats (I) and some Dogs are Cats (II)—logically follow.
Which of the following is correct? 
Look at this series:
U32, V29, ____, X23, Y20, ....
What number should fill the blank?