Answer:
IgE
Explanation:
Immunoglobulins can be described as antibodies that are found in blood and other bodily fluids of humans and other vertebrate animals. And their major function is that they help identify and destroy foreign substances such as microbes such as bacteria and protozoan parasites. 
They are known to be produced by produced by plasma cells (white blood cells).
Immunoglobulins are classified into five categories: IgA, IgD, IgE, IgG and IgM. And are distinguished by the type of heavy chain they contain. IgG molecules possess heavy chains known as γ-chains; IgMs have μ-chains; IgAs have α-chains; IgEs have ε-chains; and IgDs have δ-chains.
In this case, IgE is the immunoglobulin that attach to and sensitize mast cells and basophils.
 
        
             
        
        
        
The correct answer of the given question above is option A. The line of defense that his immune system is exhibiting in this situation is the first line of defense. The first line of defense includes the physical or external line of defense of the body that are responsible for inhibiting of the entry of foreign microorganisms. Such include the skin, tears, cilia, mucus, urine flow and even stomach acid.
        
                    
             
        
        
        
Definitely i would expect them to concern themselves with your problems when they are so beset with their own. Beset means having a lot of trouble with something, or having to deal with a lot of something causes problems. For example in a sentence; With the amount of traffic nowadays, even a trip across town is beset with dangers.
        
             
        
        
        
The scientific field of study that examines the relationships between biology and psychology, and how they influence behavior and cognition. For example, biopsychology examines topics such as how your eyes are able to inform your brain what you are reading, how the brain interprets this information, and how your brain communicates with your hand to move the mouse and click on different links.
https://study.com/academy/lesson/what-is-biopsychology-definition-basics.html
        
             
        
        
        
The answers are "<span>gravitational, electric, and magnetic fields." When too electrons rub against each other that creates a electric field. Electrons often stick together which causes a gravitational, and sometimes magnetic fields.  
Hope this helps!</span>