Which of the following would be an example of symbiosis?
A. The animal feeds on the plant.
B. The plant is toxic to the animal.
C. The paper is made from a tree.
D. The water helps the plant to grow

None of these options is correct.

Explanation:

As in first option animal show herbivorous behaviour by eatin plant as well as in second option  plant is toxic for animal .

while symbiosis is a process in which two animals stay together to harm each other or to help each other or for some other conditions but in these options there is no such situation here.

methane because it has a double bond in the structure