Answer:
Kelp is eaten by sea otters. Kelp is a large, brown plant that grows in the sea and is used in some foods and medicines
Answer: The correct answer is black because the product of its side and mass is lower.
Explanation: Density of a substance is defined as the mount of matter that can be stored in a given volume.
Mathematically,

As, density is inversely proportional to the volume of the substance.
The substance will be more denser if it has less volume and it will be less denser if the volume is more.
We are given two cubes having different sides.
Volume of the cube is calculated by using the formula:

where, a = side of the cube.
Black: The side of this cube is 2 and volume will be =
Yellow: The side of this cube is 3 and volume will be =
As, the volume of black cube is less. So, this cube will be more denser.
Density of black cube: 
Density of Yellow Cube: 
Hence, black cube will be more denser because the product of its side and mass is lower.
<span>B. A producer supplies energy for the consumers in the ecosystem.
In science, a producer is an organism that can create it's on food and serves as food for a consumer. An example of a producer could be seaweed, or algae.
</span>
Nucleoid is the answer
Cheers!!!
By the excretory system through the large intestine