Ruben and Brenda are a married couple filing jointly with an adjusted gross income of $140,000 in 2022. They have four children who they support. The 15-year-old is in high school. The other three children are full-time students temporarily away at college. The 19 -year-old is a sophomore, and she earned $5,000 working at the library. The 21-year-old is a senior in college, and he earned $8,000 from a summerjob. The 23 -year-old has been in graduate school the whole year, and she earned $10,000 from various jobs throughout the year. The parents paid the following higher education expenses: 19-year-old: $5,000 tuition and fees; $500 books 21-year-old: $6,000 tuition and fees; $600 books 23-year-old: $9,000 tuition and fees; $700 books How much is the couple's Lifetime Learning Credit for 2022? a. $2,000 b. $0 c. $1,940 d. $4,000 e. $1,800