Answer: D is the correct answer.
Explanation: Well..it's talking about how I was feeling very sorrowful about the accident I heard about.
A. hemos sentido..no because it means that we ALL have felt..and no, it's just me
B. han sentido..no because it means that you all have felt, not including me.
C. has sentido..no because it's saying "you have felt" and it's talking about me
D. he tenido..yes because it's finally talking about just me