In order to create a basis on which to compare and contrast, you should
a. generate questions.
b. formulate arguments.
c. create a thesis statement.
d. write an attention-getter.

The answer to your question is

A. Generate questions

I did the T4L test and got it right>>>> Have a good day.

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.

even though you have attached neither the chart nor the generalizations, i have located them online. the right answer is d, since they are asking you about a generalization. you can only infer from the chart that between 2008 and 2009 the number of employed workers decreased significantly (from over 115 millions to 107 millions approximately), which signals some type of economic crisis.