Which option will joan use to get a glimpse of how her presentation will look like when she presents it to her audience

She should use slideshow

There are number of software and different options for the presentation of slides and other documents for the purpose of office work, studies and other tasks etc. So, for that reason the presentations is first well prepared then there are certain steps taken to double check the whole process knowing more about the slides design and the arrangement of each bit or word inside the slides. As, it will give more knowledge about the certain task or information inside the given number of slides.While, inside the power point and other applications there is a set of data which is well designed and then double check by just viewing it on "the slideshow option given at the left bottom corner of the screen". As, there are different other keys by dialing or holding them on the keyboard can make the slides to be clearly viewed on the screen for the person to analyze its each bit or information that is present inside the document arranged or generated by the user.

You aren't giving enough information. what kind of "tool" do you mean? if you want an opinion, then jeremy should use a computer to show how his web will look like.