Hello there!
Let's look at the options:
B) to explain the nutrition information for chocolate éclairs. ⇒ the passage doesn't discuss nutrition information, so this option is incorrect.
C) to explain how to insert different fillings into chocolate éclairs. ⇒ the passage does not discuss this, so this option is incorrect.
D) to describe the taste of ingredients used to make chocolate éclairs. ⇒ The ingredients are listed and not gone into much detail, so so this option is incorrect.
This leaves us with option A), to explain the procedures for preparing chocolate éclairs, as your answer. I hope this helps!