Hello there!
Your answer would be A). High school diploma
The reason why this would be the correct answer is because as a miner, you don't really need that high of an education to get the job. Generally, you would at least need a high school diploma, due to the fact that they want the people that want to be miners to have a basic understanding of education. Getting a job as a miner is great for people that doesn't have a college diploma or degree of any kind. Even though you only need a high school diploma, the people would still need to go through long hours of training. Then you would need to take more courses if you want to be licensed.
It all really depends on what type of miner the person is trying to be, but generally an individual would only need a Highschool diploma to get started. Then after that, they just need to go through training in order to be a miner.
Some mining career paths do need a college level education though, but I'm pretty sure the question is talking about it generally. Secondary training is sometimes necessary to become a miner.