Debug build is the complete symbolic debug information which is emitted to help while debugging applications. This is also refer as code optimization which is not taken into account. However , release build the symbolic debug info is not emitted and the code execution is optimized. These can be divided as below :
(1)event-driven
(2)by polling for changes
(3)On-demand
(4)All of the options
So here all the options are correct answer.