Final answer:
When a number cube with numbers 1 to 6 is rolled, there are 6 possible outcomes, corresponding to each face of the cube.
Step-by-step explanation:
When a number cube with the numbers 1 through 6 is rolled, each face of the cube represents a different outcome. Since there are 6 faces on the cube, each with a unique number from 1 to 6, there are 6 possible outcomes. The possible outcomes are 1, 2, 3, 4, 5, and 6. Therefore, the correct answer to the number of total outcomes when rolling the die once is a) 6.