Terry was ill for three months and missed work during this period. During the illness, Terry received $4,500 in sick pay from a disability insurance policy. What amounts are included in Terry's gross income under the following independent circumstances? Note: Leave no answer blank. Enter zero if applicable. Required: a. Terry has disability insurance provided by his employer as a nontaxable fringe benefit. Terry's employer paid $2,800 in disability premiums for Terry this year. b. Terry paid $2,800 in premiums for his disability insurance this year. c. Terry's employer paid the $2,800 in premiums for Terry, but Terry elected to have his employer include the $2,800 as compensation on Terry's W-2. d. Terry and his employer share the cost of the disability insurance. Terry's employer paid $1,800 in disability premiums for Terry this year as a nontaxable fringe benefit, and Terry paid the remaining $1,000 of premiums from his after-tax salary. Note: Do not round intermediate calculations. Round your answer to the nearest whole dollar amount.