The Ohio State University pedestrians were more likely to cross streets unsafely if they were talking on a cell phone. This best illustrates the impact of

50% i think

explanation:

the secretary of defense is the principal defense policy advisor to the president. under the direction of the president, the secretary exercises authority, direction, and control over the department of defense.

as you did not provide any choices for me to choose from to give you a direct answer, this is the only information i can provide.