National border is the type of border among the following choices given in the question that would likely have the most protection. The correct option among all the options that are given in the question is the third option or the penultimate option. I hope the answer helps you.
<span>The location where Christians began to
organize the crusade against Constantinople is Venice. The Crusades were a
progression of religious wars among Christians and Muslims. <span>In
1182, madden people of Constantinople had assaulted the Venetians in
Constantinople. The Venetians in this way had an explanation behind craving
revenge.</span></span>
The Sumerians which was an ancient civilization from Mesopotamia were believed to be the first people to make and use a wheel. This invention is vital to many conveniences we have today :)<span />
I’m pretty sure it’s all but D
