D is one way to tell a chemical change has occurred
Judging from your other questions, I would guess the Aztecs, because they had an extremely advanced civilization relative to their time period. However, you might want a second opinion to verify this. Hope this helps.
Texans wanted independence from Mexico because of Mexico's abolition of slavery, increase in tariffs, and the rise of Santa Anna. Texas, being Mexican territory, was subject to Mexican laws and policies. In 1831, Mexico abolished slavery.
During the middle ages, the Jews engaged in forming guilds.
