Final answer:
The center of the hyperbola is (0, 0).
Step-by-step explanation:
The given equation of the hyperbola is x²/25 - y²/a. To find the center of the hyperbola, we compare it with the standard form (x - h)²/a² - (y - k)²/b² = 1 for a horizontal hyperbola. In this case, the center of the hyperbola is at the point (h, k), which is (0, 0). Therefore, option (a) (0, 0) is the correct answer.