Explanation: The tone of a text or sentence is the author's or speaker's attitude towards the audience, the subject or even the characters of the text. There are many different kinds of tones, like: positive, negative, objective, sad, angry, etc. In the given passage the speaker uses a sarcastic tone to make a critique about the benefits that are only for people with a lot of money.
A: A new blood test makes it easier-and safer-to detect concussions.
Explanation:
The main idea of the passage is A new blood test makes it easier—and safer—to detect concussions.
Notice the phrases question the use of and proposed an alternative way. They suggest that the main idea involves a possible solution to a problem. Here, the main idea is that the problem of detecting concussions without radiation could be solved by a simple blood test.
