In general, which of the following is a true statement about population sizer
a. If birth rate < death rate, population size increases.
b. If death rate < birth rate, population size decreases.
c. If birth rate > death rate, population size increases.
d. If death rate > birth rate, population size increases.

Im confident the answer is C.

Explanation:

If the birth rate increases then the population size increases! :)  

C. If birth rate is greater than death rate, population size increases.

Explanation:

None of the other options make sense. For instance, A. says, "birth rate is less than death rate so population size increases." How can there be more deaths than births and there be a population increase? You can continue through all of them with the same analyzing technique. :)

i'm guessing this is from edg enuity so the answers would be, from top to bottom,

theodor schwann

matthias schleiden

robert hooke

rudolph virchow

anton van leeuwenhoek

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.