Answer:
The correct answer is a. sugar
Explanation:
Even though caffeine is also known for uprising the energy levels to a point where it could cause insomnia, the excess of sugar usually causes an increase in heart rate and insomnia. Also, coca-cola has a bigger amount of sugar than caffeine, so it explains how these high quantities could affect Xi's health. 
 
        
             
        
        
        
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✧・゚: *✧・゚:*    *:・゚✧*:・゚✧
❖ The homologous chromosomes (sister chromatids) move to opposite poles of the cell. The sister chromatids are pulled to opposite poles by spindle fibers.
~ ʜᴏᴘᴇ ᴛʜɪꜱ ʜᴇʟᴘꜱ! :) ♡
~ ᴄʟᴏᴜᴛᴀɴꜱᴡᴇʀꜱ 
 
        
             
        
        
        
Answer:
E. thickening of the tunica intima and loss of elasticity in the tunica media.
Explanation:
Arteriosclerosis is characterized by thickening of the tunica intima and loss of elasticity in the tunica media.
 
        
                    
             
        
        
        
Answer:
peptide antigens by MHC class II molecules
Explanation:
Helper T cells are activated by peptide antigens by MHC class II molecules. These antigens express on the surface of antigen-presenting cells (APCs). After activation, the T helper cells divide and secrete cytokines  to assist the immune response.