A “guillotine” was an apparatus designed for efficiently carrying out executions by beheading. The device consists of a tall frame with an angled blade, which makes it a contraption( a device usually used for unsafe purposes) hence option C is the correct answer.
Option A is incorrect because “guinea pig” is a person or thing used as a subject for experiment, which is not the same as a contraption, hence incorrect.
Option B is incorrect because “gabardine” means a smooth, durable twill-woven worsted or cotton cloth, which is definitely not a contraption for beheading hence it is incorrect.
Option D is incorrect because an “icicle” means a hanging, tapering piece of ice formed by the freezing of dripping water, which is not a contraption used for beheading hence it is incorrect.