What is a restriction involving personal cell phone use for soldiers in uniform?

The correct answer highlights an important policy regarding personal cell phone use for soldiers in uniform. This restriction is in place to maintain professionalism and ensure that service members remain focused on their duties and responsibilities. When soldiers are in uniform, their conduct reflects on the military as a whole, and there's an expectation for them to uphold certain standards, which includes limiting distractions.

Allowing phone conversations while in uniform could compromise the soldier’s ability to pay attention to their surroundings and to the tasks at hand. It can also disrupt the overall discipline and decorum expected within the military environment. Thus, restricting the use of personal cell phones for talking while in uniform helps enforce a culture of attentiveness and respect for the military's values and standards of conduct.

The other options suggest actions that soldiers might still engage in, such as texting and using phones in different modes. However, these may not necessarily align with the strict guidelines focused on minimizing communication distractions in active duty situations.