Central planning refers to
a. markets guiding economic activity. today many countries that had this system have abandoned it.
b. markets guiding economic activity. today many countries that did not have this system have implemented it.
c. government guiding economic activity. today many countries that had this system have abandoned it.
d. government guiding economic activity. today many countries that did not have this system have implemented it.

The correct response is Option C: Government guiding economic activity. Today many countries that had this system have abandoned it.

Explanation:

Central planning is when the government controls many mechanisms in the economy and they set the terms for how companies are allowed to compete in the market and how investors are allowed to invest. There is also generally public ownership of production and the government spearheads the  allocation of resources in this kind of economy.  Those countries that adopted communism in the past  (including those based on the Soviet model) are examples of countries that once had a central planning economy but that have since dropped this kind of economic model.