Final answer:
In 'The Pilgrim's Progress' by John Bunyan, it is Giant Despair who encourages harsh punishment for Hopeful and Christian in Doubting Castle, making 'B) Giant Despair' the correct answer.
Step-by-step explanation:
The character who encourages harsh punishment for Hopeful and Christian in Doubting Castle is B) Giant Despair. In John Bunyan's allegorical novel The Pilgrim's Progress, Giant Despair is the menacing owner of Doubting Castle, where the protagonists, Christian and Hopeful, are imprisoned after losing their way on the journey to the Celestial City. Giant Despair beats them, starves them, and suggests they take their own lives to end their suffering.
The correct answer is in stark contrast to the other options, as Apollyon and Giant Slay-Good are different characters that Christian encounters, with Apollyon representing a spiritual adversary he battles earlier in the story, and Giant Slay-Good not being related to the specific incident at Doubting Castle.