Immature B cells have:
a. Four types of defense mechanisms on their cell membrane
b. Several kinds of defense mechanisms on their cell membrane
c. One specific kind of defense mechanism on their cell membrane
d. No defense mechanisms on their cell membrane

i would say b because b cells play a significant role in fighting infections

Explanation:

hey there,

the answer is: race, color, gender, age, and sexual orientation.

: )

because health skills are tools and strategies and also practical skills are also something you need to learn (like tools and strategies) and put it in reality.