Final answer:
The set {4, 2, -2, 1} is not allowed because it contains an improper value for the orbital quantum number (l). The set {3, 1, 0, -1/2} is allowed as it satisfies all the requirements for the quantum numbers.
Step-by-step explanation:
a. The set {4, 2, -2, 1} contains an improper value for the orbital quantum number (l). The valid range for l is from 0 to n-1. Since n = 4, the maximum value for l would be 3. Therefore, this set is not allowed.
b. The set {3, 1, 0, -1/2} satisfies all the requirements. The principal quantum number (n) is an integer, the orbital quantum number (l) is less than n, the magnetic quantum number (mê) is between -l and l, and the spin quantum number (ms) is either +1/2 or -1/2. Thus, this set is allowed.