The correct answer is:
Identity property
Step-by-step explanation:
The additive identity is 0. This is the number that you can add to any other number without changing it. (A mathematical identity is based on arriving at the same number you started with.)
In this problem, the team scores 2 goals in the first half, and ends up winning the game 2 goals to 1 goal (their 2 to the other team's 1). This means they did not score in the second half; if they had, their final score would not have been 2.
This means we add 2+0 = 2; this is the additive identity.