It is B: provides for the tight regulation of all physiological variables
Explanation:
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Homeostasis:
In biology, homeostasis is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits.
Since the death rate is higher than the birth rate we can assume that it will be negative. 5-15 is -10 for their life. immigration is also lower than the emigration. 2-4 is -2. adding -2 and -10 will give us -12, hope this helps.