In the Previous Two Problems, How Long Does It Take $t = ( L / g ) ^ { 2 }$

Multiple Choice

In the previous two problems, how long does it take for the chain to fall completely to the ground?

A) $t = ( L / g ) ^ { 2 }$
B) $t = g / L$
C) $t = L / g$
D) $t = \sqrt { L / g }$
E) $t = \sqrt { g / L }$