The behavior and design of cold-formed steel buildings and walls was investigated in the Journal of Structural Engineering (May 2013). Several of the many variables measured in the study are listed below. Identify the type (quantitative or qualitative) of each variable. (Note: The dependent variable in the study was peak load of a single stud.)

a. Type of sheathing (Bare, Gypsum, or OSB)

b. Limit state observed at peak strength (local buckling, weak-axis flexural, or flexural-torsional)

c. Peak load of single stud (kilo-Newtons)

d. Linear position transducer displacement (millimeters)