Final answer:
Hannah cannot be promoted because she doesn't have enough experience. This conclusion follows based on the minimum experience requirement in her law firm.
Step-by-step explanation:
The conclusion that Hannah cannot be promoted because she doesn't have enough experience follows.
It is stated that to be promoted in Hannah's law firm, employees must have at least four years' experience practicing as a solicitor. Since Hannah has only been a solicitor for three years, she does not meet the minimum experience requirement.
Therefore, based on the information given, it can be concluded that Hannah cannot be promoted at this time.