Keyholes

Introduction

For every keyhole question, a three-dimensional object is shown on the left followed by outlines of five openings/apertures. Your task is to imagine how the object looks from all directions and then picking an option choice that has the opening through which the object could pass directly if the proper side were inserted first. Here is an example question:

Rules

1. The object may be turned in any direction before passing it through the opening. It may even be started through the opening side not shown.
2. Once the object is started through the opening, it may NOT be twisted/turned and MUST pass completely through the opening. 
3. Both objects and opening are drawn to the same scale, so it is possible for an opening to be the correct shape but too small for the object. 
4. There are no irregularities in any hidden portion of the object. If the figure has symmetric indentations, the hidden portion is symmetric with the part shown.
5. For every question, there will always be only one correct answer.