You replied to an old post and I upgraded the 1.9 plugins last time about 2 years ago ... and also the plugins for moodle 2 have been upgraded since http://moodle.org/mod/forum/discuss.php?d=182627
I don't really know what kind of drawings you expect the students to draw but several tools / plugins can draw graphs if you need them. Both that old 1.9 package and the latest 2.X packages have a plugin that creates JSXGraphs with a Geonext applet and show them in any content if JSXGraph filter is enabled and the necessary scripts are in source or on page. Moodle 2 package in http://moodle.org/mod/forum/discuss.php?d=182627 has also a plugin for drawing graphs with asciisvg, wizard (plugin) for getting Google Charts code and Wiris CAS with graph option included (disabled by default since it requires a lisence after 1000 calculations but you can as well enable the Wiris filter and plugins if you plan to use them)
You don't really need a plugin for adding Google Drawings to quizzes or any other page of moodle - all you need is an account (for yourself or your students) in Google Docs and you can create a shared drawing in Google Docs and add the link (with image button of editor if you want to include the image of editable image as well). It's a similar task as adding any non-editable image with link to that image - "dynamic images" just change the preview when people edit them... Personally I would use Google drawings mainly for real-time collaboration (up to 50 people can edit and view a Google drawing at the same time).
In fact your students could use any tools they have for drawing and just attach the drawings as files - if you used for example attachment module instead of quiz. How do you grade the drawings (which drawings are "correct") ?