Solving the Safety vs. Aerodynamic Efficiency Dilemma

[Shehezaada]

hey guys..totally confused on this question!

How is the goal of safety at odds with aerodynamic efficiency?

OK...the way I am interperting is as. How does the goal of safety interefere with the factor, or progress, of Aerodynamic Efficiency...any help on the answer and where to get started?

 

[emptymaximum]

what makes something more aerodynamic?
sleek.
what safety things affect how sleek a car is?