The snetence that convesy the meaning of the wrd oppress is option A: The poet writes about how the death of loved ones weighs on her.
Oppresed may be defined as: to burden spiritually or mentally : weigh heavily upon
In this particular case the autho may want to refer to how the burden death of loved one may impact on the life of a person.
An example of the word oppress in a sentence: oppress by intolerable guilt