The vertical axis ranges from 0 to 100 in increments of 10. The horizontal axis lists dates from 1776 to 2018. The data is as follows. 1776: Wood, 100%. 1801: Wood, 100%. 1826: Wood, 100%. 1851: Wood, 90%. Coal, 10%. 1876: Wood, 65%. Coal, 34%. Petroleum, 1%. 1901: Wood, 20%. Coal, 61%. Petroleum, 3%. Natural gas, 3%. Hydroelectric, 3%. 1926: Wood, 5%. Coal, 65%. Petroleum, 20%. Natural gas, 7%. Hydroelectric, 3%. 1951: Wood, 2%. Coal, 38%. Petroleum, 40%. Natural gas, 16%. Hydroelectric, 4%. 1976: Wood, 20%. Petroleum, 45%. Natural gas, 29%. Nuclear, 2%. Hydroelectric, 4%. 2001: Coal, 25%. Petroleum, 35%. Natural gas, 20%. Nuclear, 18%. Hydroelectric, 1%. Other renewable, 1%. 2018: Coal, 15%. Petroleum, 35%. Natural gas, 30%. Nuclear, 12%. Hydroelectric, 1%. Other renewable, 7%. The values used in the description are approximate.

Question

Which has been the primary source of energy in the most recent century? hydroelectric and other renewables
hydroelectric and other renewables

wood and nuclear
wood and nuclear

petroleum, natural gas, and coal
petroleum, natural gas, and coal

wood and coal

Answer 1

The primary sources of energy in the most recent century (from 1918 to 2018) have been petroleum, natural gas, and coal. In 2018, coal accounted for 15%, petroleum for 35%, and natural gas for 30%. Therefore, the correct answer is:

petroleum, natural gas, and coal