How to write a story about the saying knock on wood

Knocking on wood is thought to come from the folklore of the ancient Indo-Europeans, or possibly people who predated them, who believed that trees were home to various spirits. Touching a tree would invoke the protection or blessing of the spirit within

Explanation:

the phrase “knock on wood”—or “touch wood” in ... practice to a 19th century children's game called “Tiggy Touchwood,” a type of tag.

the answer for 3 is b and the answer for 4 is d