Final answer:
The Raffia palm is an excellent competitor in the moist, dense tropical rainforest due to its broad leaves that maximize sunlight absorption. Lithops and Mormon tea are not suited for rainforest conditions as they are adapted to arid environments.
Step-by-step explanation:
In a dense and moist tropical rainforest, where light can be scarce on the forest floor, plants have adapted in various ways to ensure they can absorb large amounts of sunlight. Considering the options given, the Raffia palm would be an excellent competitor in such an environment. This palm species typically has broad leaves to maximize sunlight capture. In contrast, Lithops are adapted to desert conditions with minimal leaf surface area to reduce water loss, and Mormon tea is adapted to more arid environments.
Plants like epiphytes, which include bromeliads, ferns, and orchids, grow on other plants and can also compete well in rainforests by absorbing water and minerals from the air and the supporting plants. They have specialized tissues and structures like funnel-shaped leaves for water collection. However, among the options listed, the Raffia palm with its large leaves is specifically adapted to capture more sunlight in the lower light conditions typical of a rainforest floor.