The amount of social security benefits received by an individual that he or she must include in gross income:

a. may not exceed the portion contributed by the employer.

b. may be zero or as much as 85% of the social security benefits received, depending upon the taxpayer's social security benefits and other income.

c. may not exceed 50% of the social security benefits received.

d. is computed in the same manner as an annuity [exclusion = (cost/expected return) × amount received].

e. none of these choices are correct.