Final answer:
The Hebrew three-letter root 'SDR' leads to the term 'seder,' which is a special ceremonial meal during Passover, where the haggadah is used to narrate the Exodus story.
Step-by-step explanation:
The Hebrew language is based on three-letter roots which form the basis of many different words with related meanings. From the root letters "S", "D", "R", we get such words as "Sidrah", which is a Torah reading, "Siddur", a prayer book used in Judaism, and another term related to Jewish religious practice: seder. The word seder refers to a special ceremonial meal that takes place during the Jewish festival of Passover, highlighting the escape from slavery in Egypt. The haggadah, which is the book used to narrate the story of the Exodus during the Passover seder, plays a central role in this ritual meal. The correct answer to the student's question is therefore (a) Seder.