Correct Option: C

Macrocystis pyrifera is a giant kelp and the largest of all algae and plants. It is the fastest-growing organism. They can grow at a rate of two feet a day to reach over 50 metres long in one growing season. Populus tremuloides is the largest tree, Armillaria ostoyae is the largest among the fungi, Macropanesthia rhinoceros is the Australian giant burrowing cockroach.