To accurately compare the rate of return on one investment with another, they should be:

Measured over equal time periods.

Explanation:

To get an understanding of the rate of return you first need to lay down a period of time that you can use as a baseline when comparing the return of each investment.

answer: a. the kind of population living in your neighbourhood.

the census explorer data tool by the us census bureau allows the user to zoom in on any neighbourhood within the united states and find the kind of people residing in that by race and age.  

the tool needs to needs to be used twice – once in order to find what type of people reside in a neighbourhood, and then to see the age groups of the people in the same neighbourhood.

a. primarily outdoors, responding to emergencies and protecting people.

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