Answer:
nucleus
Step-by-step explanation:
The organelle would most likely be the nucleus.
The nucleus happens to be a membrane-bound organelle that is somehow round in shape. It houses most of the genetic components of the cell, including proteins and nucleic acids in the form of DNA.
Fungi themselves belong to the eukaryotic category of living organisms and as such, every fungus cell is expected to have a nucleus and other membrane bound organelles such as mitochondrion.
Hence, the organelle would most likely be the nucleus of the fungi cell.