What biblical metaphor illustrates the difficulty for the rich to enter heaven?

The choice referencing "a camel through a needle's eye" is considered correct because it originates from a well-known biblical passage found in the Gospel of Matthew. In this metaphor, Jesus uses the image of a camel, which is a large animal, trying to pass through the eye of a needle, a very small opening, to illustrate the challenges that wealthy individuals face in achieving spiritual salvation. This metaphor emphasizes that just as it is virtually impossible for a camel to pass through such a narrow space, it is exceedingly difficult for those attached to their wealth and material possessions to enter the kingdom of heaven.

The other options do not reflect biblical teachings or well-known metaphors related to wealth and spiritual entrance. The concept of wealth hindering spiritual growth is a fundamental theme in Jesus' teachings, and this particular metaphor poignantly captures that idea through vivid imagery.