In exchange for land, a knight agrees to be a sort of sub-vassal to a vassal. This agreement was known as Subinfeudation .
Answer: Option 4
Explanation:
In the feudal system, the knights were granted the potion of land for their usage in return for their services to the feudal tenants or other superiors. In a way, it was a mode of paying fees to the knights and this agreement was named as subinfeudation and the holding was called as sub-fee.
This practice was prevalent until 1290 when the statute of Quia Emptores was passed which outlawed this practice of paying the knightâs fee in terms granting a piece of land.