The healthiest way to cope with grief from the options provided is:
"It was pretty hard, but Kelly just listened when her Grandma kept talking about her Grandpa after he died."
This response indicates that Kelly is supporting her Grandma by letting her express her feelings, which can be an important part of the grieving process. Listening and being present for someone who is grieving can help both the bereaved individual and the listener process their emotions in a healthy way. The other options involve avoidance or withdrawing, which are generally not considered healthy coping mechanisms.