sales reps at universal containers use salesforce on their mobile devices. They want a way to add new contacts quickly and then follow up later to complete the additional information necessary. What mobile solution should an app builder recommend

Build a global action to create Contacts

Explanation:

Based on the information given the mobile solution that an app builder should recommend should be GLOBAL ACTION because global action enables new contact to be created quickly ,Global actions also enables the creation or update of records as well sending email, all without leaving the page the person is working on which is why GLOBAL ACTION is often recommended because it saves time.