The correct answer is option c. "10 inches per day".
Explanation:
Kelp plants are a group of large brown algae seaweeds known for their sizes and fast growth rate. In average, kelp plants grow 10 inches per day in wild conditions, but giant kelps and kelps of the genre <em>Macrocystis</em> and <em>Nereocystis </em>can grow even faster than this rate. Kelp plants usually grow together in "underwater forests" (kelp forests) creating refugees for sea animals.
