Primary, so the first option, or option A
Producers rely on light because that is what they use to "produce" food. Consumers, however, also rely on light, because first of all they need to see, and second of all, the light fuels growth of producers, which in turn, when consumers eat the producers, promote growth of other consumers.
Great question :)
Histamines are chemicals released by the body as an allergic response.They help the body by reacting when their are "intruders" so when enters, histamine acts as a messenger and sends out a signal for the body to create a reaction helping to get rid of teh intruder through some type of reaction.