If the Political Leaders of a Country Want to Promote

If the political leaders of a country want to promote economic growth, which of the following policy alternatives would be most effective?

A) imposition of price controls on agricultural products in an effort to keep food cheap
B) a public-sector investment program financed by highly progressive taxation
C) low taxes, a monetary policy consistent with long-run price stability, and the abolition of price controls and trade restrictions
D) expansionary monetary policy designed to keep interest rates low