Problem 1: b
Problem 2: d
Problem 3: d
Problem 4: a
Problem 5: c
Problem 6 : c
Problem 7 : e
Problem 8 : c
Problem 9 : c
Problem 10 : b
Problem 11 : a
Problem 12 : b
Problem 13 : d
Problem 14 : c
Problem 15 : c
Problem 16 : b
Problem 17 : d
Problem 18 : b
Problem 19 : d
Problem 20 : d
Problem 21 : d
Problem 22 : c
Problem 23 : b