What is the most important concept that Dr. Robling wanted to communicate?

the answer is true.  i do believe this is the answer because of the amount of wrecks people get into each year.  if you double this with avoiding those so said wrecks, that would make you a "skilled" driver.

according to the song of roland, the characteristics of an ideal knight are: loyalty to the king, skilled warriors and horseman, valiant, bold, courageous, strong and proud in battle. they should be determined to fulfil their duties and willing to die to make their people safe.

hi there, i would say your answer is:

b. there is a fixed quantity of resources and technology available.

hope that : )