Run out of steam

Do you know the English expression “run out of steam“? Read the conversation below. Can you guess the meaning?

Vincent: How was Mr. Brown’s speech at the conference yesterday?

Gregory: It was OK, but very long. He ran out of steam near the end. He should have finished it a lot earlier.

Does it mean:

a) run out of energy

b) run out of words

c) forget what to say

d) need a rest

The answer is below! ↓

 

Answer: a) run out of energy