17. Standard Deduction and Filing Requirements. (Obj. 6) For each of the following individuals, determine (1) their total standard deduction and (2) the amount of their gross income threshold (and unearned income threshold for dependents) they use to determine whether they must file an income tax return for 2020. a. Steve is 36 years old. His filing status is single and he has 20/20 vision. b. Maggie is a 70 years old widow. Her son claims her as a dependent. Maggie is permanently blind. Her gross income includes investment income, but no earned income. c. Same as in Part b., except that Maggie is not claimed a dependent on her son's return. d. Jeannie and Tom file a joint tax return. Jennie turned 65 on January 1, 2020; Tom turned 69 on March 8, 2020. Neither have any vision problems. e. Sally files a separate tax return from her husband. She is 40 years old and blind. f. Joe's wife died in 2020. Joe is 70 years old and has good eyesight. At the time of her death, Joe's wife was 60 and had good eyesight. Joe does not itemize