Question

the dominant political party in mexico for most of the twentieth century was the institutional revolutionary party national action party labor party ecologist green party of mexico

Explanation:

The Institutional Revolutionary Party (PRI) held power in Mexico for most of the 20th century. It was founded in 1929 and dominated Mexican politics until the late 20th century. The other parties listed either came to prominence later (like the National Action Party which won the presidency in 2000) or are more recent creations (such as the Ecologist Green Party of Mexico) or less dominant (Labor Party).

Answer:

Institutional Revolutionary Party