As an HR department employee at an investment bank, Tania receives an email form her department which asks her to study the behavior of a colleague Mary, in terms of Mary$$s attention with her work. For this purpose, Tania needs to examine Mary$$s behavior and see if she pays attention to her tasks and is free from distractions. Which of the following is Tania conducting?

observer$-$ratings survey

knowledge survey

focus group survey

participant observation

informational interview