Wilma, Xavier, Yaska and Zakir are four young friends, who have a passion for integers. One day, each of them selects one integer and writes it on a wall. The writing on the wall shows that Xavier and Zakir picked positive integers, Yaska picked a negative one, while Wilma’s integer is either negative, zero or positive. If their integers are denoted by the first letters of their respective names, the following is true: W⁴ + X³ + Y² + Z ≤ 4; X³ + Z ≥ 2; W⁴ + Y² ≤ 2; Y² + Z ≥ 3. Given the above, which of these can W² + X² + Y² + Z² possibly evaluate to?