The best answer would be "She evinced an interest in drama, so I took her to the play."
The definition for evinced is to show or express clearly. So, this is the only answer that makes sense.
I hope this helps!
Homer tells you in the narrative i think..
To begin with letter 3, It could be said that the main theme is determination because Walton feels confident about the voyage and he is ´determined' to go on with it despite the weather conditions.
As regards letter 4, we might say that the theme may be trust and friendship because Frankenstein and Walton met and he is will to tell him the his story. So this letter might be seen as the beginning of their friendship.