I think its a density dependent limited factor
Answer:
A
Explanation:
I think an untreated water can carry disease causing organisms and make people sick
Follicle stimulating hormone (FSH) and Luteinizing hormone (LH) are Gonadotropins stimulated in the gonads. In females, they are located in the ovaries. They are not needed for life yet important for reproduction. Progesterone which is being secreted in corpus luteum is needed for maintenance of pregnancy thus if a female has a low FSH and LH it will affect the chance of her be pregnant.
I am sorry, I am not good in this area but, I found a site that could help you: http://www.chemicalelements.com/elements/ca.html
I know I am not supposed to post links but, I found help