Choice Ahoice D is the correct answer. When an equation equals zero, we still use the same solving strategy.

1. Start with the equation: $x - 25 = 0$
2. Add 25 to both sides: $x = 0 + 25$
3. Simplify: $x = 25$
4. Verify: $25 - 25 = 0$ ✓

This problem demonstrates that when we subtract a number from itself, we get zero: $a - a = 0$.

💡 Zero Property: The equation $x - a = 0$ always has the solution $x = a$. This is because only when $x = a$ will $x - a = 0$.

Choice Ahoice C is incorrect because zero is the result of the equation, not the value of $x$. The right side being zero doesn't mean $x = 0$.

Choice Ahoice D is incorrect because this is the negative of the correct answer. Some students might incorrectly think $x = -25$ makes the expression zero.

Choice Ahoice C is incorrect because this might come from treating the problem as division: "25 divided by something equals 0 can't work, so maybe 1?" This reasoning is flawed.