The poem “richard cory” by edwin arlington robinson explores how the theme of dissatisfaction and the mentality that “the grass is greener on the other side” affects all humans. which lines in this excerpt reflect those themes?
a.and he was rich—yes, richer than a king—
and admirably schooled in every grace
b.to make us wish that we were in his place.
c.so on we worked, and waited for the light
d.went home and put a bullet through his head.

The question states that "Richard Cory" explores that "the grass is greener on the other side" affects all humans.

Because of this, I believe the answer is B and D.

With B and D, you can see both sides, both people from opposite sides of "the grass" who wish to be on the other side.

B. "To make us wish that we were in his place" says this directly, while D. "Went home and put a bullet through his head" implies it. He was obviously unhappy with his life, and wished for something else.

I know I'm late, but I hope this can still help someone.

The best and the correct answer among the choices provided by the question is the second choice or letter B.

The line "To make us wish that we were in his place." reflect the themes of the excerpt.
I hope my answer has come to your help. Have a nice day ahead and may God bless you always!

Only three trees has grown in my backyard.
Answer= letter B 
Hope I could help!