Choice A is the correct answer. Calculate slope.

1. Initial: 50.
2. Increase: $10\%$ of $50 = 5$.
3. Rate: 5 per unit x.
4. Equation: $y = 5x + 50$.

💡 Strategic Tip: Don't confuse percent rate (exponential) with fixed amount based on percent of start (linear).

Choice B is incorrect because uses 0.10 directly. Choice C is incorrect because swaps. Choice D is incorrect because exponential-ish.