An excellent, inexpensive, and readily accessible method for assessing customers' service expectations is
a. customer complaints.
b. syndicated data services.
c. employee empowerment programs.
d. distributive fairness analysis.
e. management by objective programs.

a. customer complaints .

Explanation:

Customer complaints -

It refers to the problems or dissatisfaction faced by the customer regarding any of the product or services , is known as customer complaints .

This complaints helps the company or the organisation , to get the feedback of the product from the customer and to helps the company to improve or alter the product so as it make it more useful for the consumer and , which in turn will increase the production and profit of the company .

Hence , It is considered to be most appropriate  , inexpensive method to deal with any problem .

it´s related to his charming character.

beauty is not everything, although we can joke that girls only care about the physical or material aspect, the truth is that a real woman looks at more important things, besides intelligence and personality, there are other attitudes that make irresistible to men who are 'unattractive'.

for example develop your sense of humor.

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.