Fundamental to understanding a particular time in history is :

The correct answer is C. The uncovering and careful reading of primary sources.

This element is fundamental to understanding a point in time because a primary source provides direct evidence about a historic event, person, place or situation. This original information allows other investigations as a point of reference.

Primary sources can be diaries, interviews, fieldwork, pictures, books, ancient texts, government documents., and historic records.

D

Explanation:

I'm assuming A means paying "taxes" not "Texas". Anyway, the Mexican government tried to restrict Texas using all of these methods except D.

D is the correct answer.