While playing soccer, carla slides across one of the lines on the field. when she stands up, what base does she dust off? calcium hydroxide ammonium hydroxide zinc hydroxide potassium hydroxide

Option A, Calcium hydroxide

Explanation:

Sports pitches are regularly marked with the chalk and limestone. However, in earlier sports events,  wood shavings and dust were also used.  

Since most of these sports are played on grass surfaces, marking through lime has proved much convenient than other materials.  

Chalk and limestone materials or hydrated lime (CaOH) is crushed into powder form and used for marking the pitches. Since it is white in color, it could easily reflect the light  and hence produces good  visibility.

Hence, option A is correct

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.