Final answer:
The phrase that best supports the conclusion that online identity can be easily manipulated is 'Users can edit their profiles freely, altering details to present a desired image.'
Step-by-step explanation:
In the text, the phrase that best supports the conclusion that online identity can be easily manipulated is: 'Users can edit their profiles freely, altering details to present a desired image.' This phrase suggests that individuals have the ability to change information on their online profiles to project a specific image of themselves, which indicates that online identity can be easily manipulated.
The phrase that best supports this answer is: 'Users can edit their profiles freely, altering details to present a desired image.' This phrase directly addresses the manipulation of online identity through the act of freely editing and altering profile details.