Step 1: Condition for a Square
For four lines to form a square, the slopes of perpendicular lines must satisfy:
\[
m_1 \times m_2 = -1
\]
Step 2: Finding \( \alpha, \beta, k \)
Using the conditions for perpendicularity, we solve for \( \alpha, \beta, k \) and compute:
\[
\alpha \beta (k+4)^2 = -512
\]
Thus, the correct answer is \( -512 \).