When Prophet Isaiah saw the glory of heaven,

The question is asking about what Prophet Isaiah felt when he saw the glory of heaven. The options are: A) he was happy, B) he felt joyful, C) he worshipped God, D) he felt unclean (which is the correct answer), and E) he said, "Here am I, send me."

Prophet Isaiah is one of the major prophets of the Old Testament. When he saw the glory of heaven, he became aware of his own unworthiness and sinfulness in comparison to the holiness of God. This caused him to feel unclean, which is why option D is the correct answer.

The feeling of being unclean is not just a physical sensation, but also a spiritual one. It is a recognition of one's own sinfulness and need for forgiveness, which is a common theme in Christianity. This experience also led Isaiah to confess his sins and seek forgiveness from God.

Overall, this question is testing your knowledge of Prophet Isaiah's experience when he saw the glory of heaven. It is important to understand the context and significance of this event in order to choose the correct answer.