Final answer:
The correct answer to what the slope in Tina's bank account problem represents is B. -$50, as it indicates the weekly rate at which her account balance decreases due to her withdrawals.
Step-by-step explanation:
The question is asking to determine the slope of Tina's bank account balance over time as she systematically makes withdrawals. When dealing with problems of this nature, where money is taken out at a consistent rate, the slope is typically the amount that is withdrawn (or deposited) at each interval. In this case, since Tina is withdrawing $50 each week, the slope of the bank account balance would be -$50 as this represents the rate of change of her balance over time. Option A suggests a positive $50 which is incorrect because her balance is decreasing and not increasing. Option C and D correspond to the initial balance, not the rate of its change. Therefore, the correct answer is B. -$50.