Final answer:
Victor's sentiment that "the cup of life is poisoned forever" reflects his deep regret for creating the monster and the resulting tragic consequences, including personal responsibility for suffering and loss of loved ones.
Step-by-step explanation:
When Victor says "the cup of life is poisoned forever," he is expressing a profound regret and despair that permeates his existence as a result of creating the monster. This statement encapsulates a mixture of emotions, including sorrow for his part in the events that have unfolded, remorse for the loss of innocent lives, and a realization of the enduring consequences of his actions. Therefore, the sentiment can be understood as a combination of mourning the loss of loved ones (b), a sense of personal responsibility for the suffering caused (d), and an insight into the tragic nature of life augmented by his actions (c).