What are internal and external regulators?
a) lipids
b) carbohydrates
c) proteins

Regulators  are proteins that guide cell to grow,replicate and perform function
External regulators are protiens outside the cell and internal inside so

internal and external regulators are Proteins
so option C is correct
hope it helps

What are internal and external regulators?
C) proteins

(a) is not correct because one does not get increased cholesterol  from lifting weights.(b) is not correct because lifting weights cannot reduce the risk of a hereditary disease.(c) is not correct because back pain isn't a benefit! and plus, if he lifts weights properly, he should not have back pain.(d) is the correct answer because his ligaments will gain mass, making it easier for him to carry heavier weights and he will also be stronger!