UI Policiesare the preferred method to dynamically control the visibility, read-only state, or mandatory status of form fieldswithout requiring a page reload.
Best Practicesuggests usingUI Policiesover Client Scripts whenever possible because UI Policies execute on the client side and are easier to manage.
Theydo not require scriptingin most cases and provide asimple rule-based approach.
Explanation of Incorrect Options:
Client Scripts (A)# Used for executing JavaScript logic in the browser, but making fields mandatory or hidden should be done via UI Policies.
Business Rules (C)# Run on the server-side and do not directly affect form fields in real-time.
UI Actions (D)# Used for creating buttons, links, or context menu actions;not for modifying field properties.
Reference:
ServiceNow Docs - UI Policies