Which of these phrases is an example of understatement?

A.
The brand new Mercedes I won in a raffle is nice.

B.
I ran into my English teacher when I went to pick up my mom at the airport.

C.
I'm exhausted because I ran in a million circles all day.

D.
I just love it when my baby brother wakes me up crying at all hours of the night.

A. The brand new Mercedes I won in a raffle is nice.

The phrase that is an example of understatement is:

C. "I'm exhausted because I ran in a million circles all day."

To determine which of these phrases is an example of understatement, we need to understand what understatement means. Understatement is a figure of speech in which something is portrayed as less important, serious, or impressive than it actually is. It involves deliberately downplaying or minimizing the significance of something.

Let's analyze each phrase one by one:

A. "The brand new Mercedes I won in a raffle is nice."
This statement seems straightforward and positive, without any indication of understatement. It expresses a positive sentiment about winning a Mercedes, but it does not downplay or minimize its significance. Therefore, option A is not an example of understatement.

B. "I ran into my English teacher when I went to pick up my mom at the airport."
This statement describes an unexpected encounter with the English teacher while on a mundane task. It seems like a casual encounter, so it can be considered an understatement. Option B could be an example of understatement.

C. "I'm exhausted because I ran in a million circles all day."
This statement is an exaggeration rather than understatement. It uses hyperbole to emphasize extreme exhaustion, rather than downplaying or minimizing it. Therefore, option C is not an example of understatement.

D. "I just love it when my baby brother wakes me up crying at all hours of the night."
This statement seems sarcastic or ironic rather than understated. It implies the speaker does not actually love the situation but, rather, finds it annoying. Therefore, option D is not an example of understatement.

Based on the analysis, option B, "I ran into my English teacher when I went to pick up my mom at the airport," is the most likely example of understatement among the given phrases.