Astudy of college graduates involves three variables: income level, job satisfaction, and one-way commute times to work. list some ways the variables might be confounded. (select all that apply.)

a.) people with long commutes will have very high incomes.
b.) a working spouse could affect all three variables.
c.) people might be very satisfied with their career as long as the income is high.
d.) people with who are very unsatisfied with their jobs will have a low income.
e.) one-way commute times may be long because affordable housing is distant from the job.
f.) people may have a career following their passion, but have a low income or a long commute.