An exploration of the factors underlying an​ economy's capital stock and its level of technology indicates that the relevant time frame is the medium long medium run. Factors that one might explore to understand the pace at which a​ country's capital stock and its level of technology are advancing include the ​(Check all that apply​.)

A. quality of its education system.
B. saving rate.
C. number of firms.
D. state of consumer confidence.
E. role of the government.