Can anyone help me out with 74c English #6 please?

Can anyone help me out with 74c English #6 please?

The passage is as follows: The reptile’s calmness amazed me, as did the _________________ and watched it peacefully rest.

I was able to eliminate f/h because Calmness and tenderness need to be put subsequently. But I got confused why J: TENDERNESS THE WOMAN SHOWED does not work.

The answer is G: tenderness with which the woman caressed her pet

I thought J would be fine because G is too long. And by reading just tenderness in G, I know that tenderness is toward her iguana.

Anybody has any idea?
Thanks!

It needs an object (something to which it refers), therefore pet must be introduced for the clause to be structurally sound. If you read the clause alone, this should become clear. (What you know from the rest of the passage does not need to be considered in this case.)