A part of me keeps wishing we'd somehow been able to share everything we discovered with Ruth. [...] The way it is, it's like there's a line with us on one side and Ruth on the other, and when all's said and done, I feel sad about that, and I think she would too if she could see it
What does the narrator express about their relationship with Ruth in the given excerpt?
a) They regret not being able to share discoveries with Ruth.
b) They feel indifferent about Ruth's absence.
c) They believe Ruth wouldn't understand their discoveries.
d) They are glad they didn't have to share with Ruth.