What document gave only parliament power to tax?

A. Westminster Model

B. Magna Carta

C. Mayflower Compact

D. Confirmation of Charters

I put answer A and it was incorrect.

The correct answer is D. The Confirmation of Charters gave parliament the power to tax its citizens. Presumably, these taxes are used to maintain/support the government and infrastructure. Sadly, these funds are often misappropriated due to lack of oversight.