Which question could be considered illegal for an employer to ask Ursula during her interview?

Asking about a candidate's native language can be considered illegal because it may lead to discrimination based on national origin or ethnicity. Employers generally should focus on a candidate's qualifications and ability to perform the job rather than delving into personal background factors that are not directly related to the job requirements.

In a job interview, employers should refrain from questions that could reveal the applicant's background in a way that might evoke biases or reinforce stereotypes. On the other hand, inquiries about prior experience, willingness to work weekends, and the ability to provide references are all relevant to assessing a candidate's suitability for the position and are considered acceptable areas for discussion during an interview.