In the story of the bronze serpent (Numbers 21:4-9), what theological significance can be attributed to God's unusual method of healing the Israelites from snake bites?

A It demonstrated God's power over snakes and other dangerous creatures. B It showed that God only answers prayers that are accompanied by a physical act. C It was a purely symbolic gesture with no real healing power. D It served as a prefigurement of Christ's crucifixion, where looking to Him in faith brings healing and salvation, even through an object associated with sin and death.