Choice Choice D is the correct answer.

1. Start with the equation: $5x + 25 = 100$
2. Subtract 25 from both sides: $5x = 100 - 25$
3. Simplify: $5x = 75$
4. Divide both sides by 5: $x = \frac{75}{5}$
5. Simplify: $x = 15$
6. Verify: $5(15) + 25 = 75 + 25 = 100$ ✓

Choice Choice B is incorrect because this results from adding 25 to 100: $125$, then $125/5 = 25$. Wrong inverse operation.

Choice Choice B is incorrect because this is the value of $5x$. You need to divide by 5.

Choice Choice A is incorrect because this results from multiplying 75 by 5: $375$.