Help me please Laboratory experiments allow scientists to make precise observations. Which one

of the following is not a laboratory experiment?​

​A counting the population of a country​

​B comparing the color of mold in three different Petri dishes​

​C measuring how much three plants grow with different amounts of light​

​D making observations about the impact of different kinds of fertilizer on

seedlings growing near the windows in the lab​

i think   the answer is c hope i'm right

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.