Answer: Daughter board
Step-by-step explanation:
A daughter board is refers to the circuit board and it is basically connected to the motherboard directly without any interruption.
It is also known as a daughter card which plugs and then extended the circuitry by connecting with the another circuit board. A mezzanine card and the riser card are the examples of the daughter board that used in the system.
According to the question, the riser card basically plus into the unique socket or the slot in the board and this is known as the daughter board.
Therefore, Daughter board is the correct answer.