One night after he heard his parents arguing, 4-year old wei had a vivid dream in which he saved his mother from being bitten by a large snake. a psychoanalyst would most likely suspect that wei's dream reflects a(n):

Wei's dream reflects Oedipus Complex.

Explanation:

In the science of psychology, complex emotions can arise in a young child, usually at the age of four, in which he has feelings of desire for his opposite sex parent and anger and jealousy towards his same sex parent.

For example in this question, Wei sees a dream after his parents light fight in which he saved his mother from being bitten by a large snake. Psychologists would interpret this dream as the desire of Wei to save her mother and protect her from any harm, whereas he thinks that his dad has no contribution towards the protection of her mother. So he must be angry with the father. All such dreams are part of unconscious mind.

explanation:

allergens: overstimulate the nerve system

neurotics: attack nerve cells

mutagens: damage or otherwise alter dna sequence

generators: cause defects during growth and development  

carcinogens: cause unchecked cell growth

i hope you get the idea according to me these are the effects that happened.