Answer:
The amount of light and temperature are examples of factors to which living things respond.
Explanation:
To understand this answer we need to see all the options.
a) necessary to live. It is incorrect even though it might look interesting. However, there is life in the dark deepness of the ocean and at below 0 Celsius degrees so it is not necessary.
b) Methods of energy production. Weel they are not the methods of energy, they are sources of energy so it is incorrect.
c) Factors to which living things respond. Is the correct option because all species can tolerate certain temperature as light, so every time they are not in their ideal condition they move to find it, otherwise their life will be at risk.
d) These factors are incorrect. because reproduction is conditioned by hormone production and maturity.
