Answer: Simulation.
Explanation:
Simulation is a process to model random events, when there is lack of theoretical reasoning in such a way that simulated outcomes closely match real-world outcomes. Researchers observe simulated outcomes to gain insight on the real world.
Given: Irina rolled a six-sided number cube repeatedly, assigning her team a number between 1 and 6 to demonstrate the probability that her team would win.
Here Irina knows and controls the truth.
Thus, the method she use to collect her data is simulation.