Devices such as a "life-preserving" coffin refers to a container that is

Devices such as a "life-preserving" coffin refers to a container that is equipped with a signaling device where any motion is detected through two mechanisms: a ring slipped around the occupant’s finger and a metal head plate. By fitting the typical hinged lid with a series of levers and springs, which activate via motion-detecting devices in the coffin, ultimately releasing the latch which were connected by wires to the coffin’s opening mechanism, with the slightest movement triggering the lid catch. The life-preserving coffin was a special burial casket which purpose is to was allow those mistakenly buried alive to safely get out. It is designed by Christian Henry Eisenbrandt in 1843. This special burial casket also features a mesh in its lid which would supposedly provide a limited supply of air post-burial.

The answer would be d because x,y = male and x,x = female so x,y is male so xxy is male with a female trait!