a.In January 2021, crude oil prices, which have been recovering for a while, increased to above $50/barrel for the first time in almost a year. Using Supply-Demand (S-D) analysis, which of the curves (S, D, or both) likely shifted, and in which direction(s)? What could explain the shift(s)? [1 line]

Chart 2. 12-month percent change in CPI for All Urban Consumers (CPI-U), not seasonally adjusted, Jan. 2020 - Jan. 2021 Percent change 2.5 2.0 1.5 * X * 1.0 0.5 0.0 Jan'20 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan'21 X X X All items All items less food and energy