FY 902 is a “circle” enclosed in a “square,” which indicates it is an instrument with a shared display or a shared control. The “902” is the “loop number.” The “F” indicates this is “flow” related, and the “Y” is saying there is some kind of conversion or computation going on. The way we know it is a “square root” conversion is from the “square root symbol (√)” on the top right hand corner of the box.

The correct answer is C, square root.