Answer
The statement that is true about the deepest parts of the ocean floor is the parts are dark all time due to lack of penetration of natural light.
Explanation
In the deepest parts of the ocean, animal live in constant darkness due to Lack of direct natural light from the sun. The Mariana Trench is the deepest point in Earth’s oceans approximated to be 36070 feet below sea level. The trench was formed due to collision of two converging plates of oceanic lithosphere.