Final answer:
Nicolaus Copernicus was the person who introduced the heliocentric model which placed the Sun rather than the Earth at the center of our solar system in the 16th century.
Step-by-step explanation:
The person who announced the idea of a moving Earth in the 16th century was A) Nicolaus Copernicus. Copernicus is known for challenging the widely accepted Ptolemaic model, which placed the Earth at the center of the universe, with his revolutionary heliocentric model. In this model, the Earth and other planets revolve around the Sun. Copernicus laid the groundwork for subsequent astronomers like Johannes Kepler and Galileo Galilei, who would further develop and prove the heliocentric theory. Nicolaus Copernicus introduced his heliocentric model to Renaissance Europe through his book De Revolutionibus. His idea turned the tide of cosmological thought and played a significant role in the advancement of modern science.