After identifying a problem you want to solve, what are the additional steps of the
design process?
design, explore, build, test, improve
design, explore, build, improve, test
explore, design, build, test, improve
explore, design, build, improve, test

Once the problem which has to be solved has been identified, the sequence of the processes to be followed should be:

Explore, Design, Build, Test, Improve.

Explanation:

The very first step should be exploring the solutions and ways to accomplish them in the most effective way possible. Next comes the designing of an application accompanied by the implementation of the solution.

Building the program or application is the next step.  Testing the developed application or program will be the next step. By testing, the developer would know about the limitation, shortcomings, and bugs.

Improving the application or program will be the last step after testing. All the bugs and shortcomings that have come up during the process of testing shall be dealt with in the improvement phase.

answer; availability;