THE GAMER NEXT DOOR

Answer: Katniss killed Coin on purpose. Katniss realised that not only was Coin responsible for the Capitol bombing and Prim's death, but that nothing was going to change with Coin in charge. Coin would use all the same power and tactics that Snow used to stay in power. Plus Coin proposed a "final" Hunger Games with the Capitol's children, even after saying there would be no more Hunger Games. Katniss knew (or at least assumed) that Coin would continue using the Hunger Games to maintain her order, which is what had been happening for the last 75 years.

Answer: President Coin ordered Peeta to join Katniss' team with the hopes that he would succeed in killing Katniss. Coin felt Katniss was a threat.

Answer: Coin was ultimately responsible. Coin sent Prim to the Capitol and then had the Capitol bombed. The rebels, led by Coin, used hovercrafts with the Capitol insignia on it to drop the bombs so that the public thought it was the Capitol bombing their children. Coin wanted Katniss to blame Snow for Prim's death to get her full support.

Bishop73

Chosen answer: They knew Peeta would trust Prim. She was always honest and did not have any ulterior motives other than wanting to help Peeta recover. Prim was someone who helped others without expecting anything in return.

raywest ★

Chosen answer: Katniss keeps up the appearance that she wants to be the one to kill Snow so that she can be in a position to kill Coin. She still hates Snow for all he's done, but sees that he's dying anyway. She realises Coin is the greater threat, and will simply rule as Snow did.