Kristen, a single taxpayer, receives two 2018 Forms W-2 from the two employers she worked for during the year. One Form W-2 lists her wages in Boxes 1, 3, and 5 as $18,700. Her other employer’s Form W-2 has $43,000 in Box 1 but only $46,500 in both Box 3 and Box 5. Kristen participated in the second employer’s 401(k) plan. She also received health care from her second employer. Lastly, her second employer provided $30,000 of group term life insurance to Kristen. 

a. What amount should Kristen report as taxable wages in 2018? 

b. What could explain the difference between Box 1 wages and Boxes 3 and 5 on her second employer’s W-2?