Answer:
D. Cytokines
Explanation:
I would utilize Cytokines to recruit more leukocytes to the battle.
Cytokines are important chemical messengers that act via receptors in the immune system of the body. They are a group of proteins made by various immune cells. Immune cells communicate through Cytokines in regulating immune response
Here are some of the animals that have names that start with S: seal, sheep, skunk, sloth, sparrow, squirrel, swan, salamander, scorpion, serval, snake, spider, stork, etc.
Hope this helps :)
