Answer:
a. both aggregate demand and long-run aggregate supply must be shifting right, and aggregate demand must be shifting farther
Step-by-step explanation:
The statement that best explains rising prices and an upward trend in real GDP is that "both aggregate demand and long-run aggregate supply must be shifting right and aggregate demand must be shifting farther."
The long-run aggregate supply shift to the right shows rising prices over the years. This is true because the higher the cost of commodities, the higher the quantity supplied.
Also, the farther shift of the aggregate demand shows there is an upward trend in real GDP. This is also true because upwards in GDP shows an increase in wages and thereby leading to the rise in demands.