Context: This is a piece of chalk. Chalk forms below the ocean floor. It is made of the body parts of tiny marine organisms. The main mineral in chalk is calcite.
Some marine organisms make hard shells. When the organisms die, these shells fall to the ocean floor. Over time, layers of broken shells can get pressed together into chalk.
What type of rock is chalk?
A. sedimentary
B. metamorphic
C. igneous
From the given choices, choose the correct answer and respond with the letter of that choice.

A