Which of the following is not an arithmetic operator?

The bridge exercise shown below is a typical icebreaker for the first lesson of the course. It clears the fairway for the upcoming course ("breaks the ice") in several manners: It reduces social reservations by providing a problem that has to be solved together, it reduces the uncertainty for the course by giving a sense of achievement when the first problem of the course is solved and it introduces first terms and concepts of the course that can be experienced by practical work. The main stakeholders of this exercise are participants of software engineering courses (novice as well as experts), but you can find managerial and communication aspects as well (see Variants below). The mission: The job for the team is to build a bridge connecting the two watersides of a river.

Requirements ? The bridge has to be self-supporting, so no pillars are allowed in the middle of the bridge. ? Pedestrians shall be able to get onto the bridge from the level of the edge. ? Of course there is no real river needed for this exercise, two tables that can be moved around do the watersides for this exercise. The building material for the bridge is plastic in form of toy Lego building bricks. Implementation For the solution of the problem the teams get ? 3 large buckets of Lego building bricks ? Two tables that can be placed in a way that there is up to 150 cm distance between them (the width of the river) Development Process ? 30 minutes for planning and prototyping (Prototyping) and ? 5 minutes for the final build from scratch (Construction) The beginning and the end of the phases is signalled by the instructor (or helper). At the end of the prototyping phase all Lego parts have to be taken apart again. After the construction phase, each bridge is tested. It must span the gap for at least one minute. If more than one bridge passes this test, an additional stress test is performed: One by one, individual Lego pieces are placed at the middle position of the bridge. The bridge collapses under the biggest load - i.e. the largest numbers of added Lego pieces - wins the competition.

Which of the following is a component of PKI?

A) Certification authority B) Registration authority C) Client nodes D) All of the above