A Quality Control Engineer Oversees the Production of Rubber Seals

A quality control engineer oversees the production of rubber seals for aircraft manufacturing.In a standard production run, 25 seals are randomly selected for destructive testing.The seals are physically stressed to their common design limit while exposed to increasing temperature, with the trial ending when the seal fails.Of interest is the temperature at which the seal fails.The variable in this experiment is:

A) the 25 seals selected.
B) the common design stress to which each seal is exposed.
C) the temperature to which each seal is exposed.
D) all manufactured rubber seals.