The most accurate answer to the question of whether using ChatGPT to generate ideas and presenting them as your own is ethical would be:
c. No, because of failing to acknowledge ChatGPT as the source of the ideas.
In academic writing, it is essential to give appropriate credit to sources of information, including AI tools. Failing to do so can be considered plagiarism. While there may be discussions about the ethical use of AI in generating ideas, presenting these ideas without attribution is generally not acceptable in academic contexts.