Final answer:
The gypsum board referred to is likely the 5/8" type X gypsum board, which is known for its fire-resistant properties and is commonly used in fire-rated wall assemblies.
Step-by-step explanation:
The type of gypsum board mentioned in the given statement is likely to be a 5/8" type X gypsum board. Type X gypsum board is specially formulated to be fire-resistant and is commonly used in the construction of walls and ceilings where a fire-resistance rating is required. It is made by adding fibers to the gypsum core that can withstand high temperatures for a specified amount of time, and the 5/8" dimension refers to the thickness of the board. There aren't any standard types labeled as Y, Z, or W gypsum boards.