Please help me, need the answer ASAP

What affected the second industrial revolution have on transportation

What was the purpose of the u.s navy's convoy system

Plz which of the following statements is the best definition of a blockade? a. a blockade is a group of soldiers recruited from a foreign country who serve for the money. b. a block it is a military tactic in which one army moves into place to face another army. c. a blockade is a wooden fence built to defend a colonial settlement. d. blockage is the shutting off of a port by ships to keep people or supplies from moving in or out.