Final answer:
In the context of a business cycle, a recession occurs from a peak to a trough. Therefore, the interval that goes from the peak (highest point just before a recession) to the trough (lowest point just before recovery) would represent a business cycle recession, which could be interval B to C if B is the peak and C is the trough.
Step-by-step explanation:
A business cycle recession is defined by a significant decline in economic activity, specifically when the real Gross Domestic Product (GDP) decreases substantially. According to the provided information, a recession occurs from the peak of the business cycle to the trough. Therefore, within a given figure showing an economy's activity, the interval that represents a business cycle recession would be the period starting just after the peak (the highest point before the recession begins) and ending at the trough (the lowest point before the recovery starts).
Without the specific figure provided, we can apply this general knowledge: if the given intervals are A to B, B to C, A to C, and B to D, and we know that a recession lasts from peak to trough, then the correct interval would be from the peak to the next trough. Answer option A. B to C might imply a decrease from peak to trough, which would signify a recession assuming point B was the peak and point C was the trough.
The intervals A to B or B to D could represent expansions if A was the trough and B the peak or if B was the trough and D the peak, and the interval A to C would span across an entire cycle, which is not specific to the recession phase alone.