AMC 8 1986 Problem 21

Suppose one of the eight lettered identical squares is included with the four squares in the T-shaped figure outlined. How many of the resulting figures can be folded into a topless cubical box?

$\text{(A)}\ 2 \text{(B)}\ 3 \text{(C)}\ 4 \text{(D)}\ 5 \text{(E)}\ 6$