The correct answer is option A
A person that is having an allergy with pollen grains should take antihistamines.
When there is an allergic reaction in the body then the body releases histamines which evokes immune response.
As a result of this the person starts sneezing, runny nose, hives et cetera.
So, one should take antihistamines to prevent the action of histamines on the body.
Carbon dioxide and hydrogen monoxide
This would be considered the synaptic cleft
Answer and Explanation: So the plant/algae take nitrogen from the topsoil by captivating through roots, such as the Glutaminic Acids, ammonium ions, or nitrate ions. Plants can't necessarily get nitrogen from instant air, however, plants obtain nitrogen through a natural process.
Hope this helps! :-)
