Which of the following words is closest in meaning to “Doldrums”?

Doldrums means a state of stagnation or low spirits.

• Correct answer - stagnation: it has the same meaning as Doldrums.
• richness: wealth or fullness - wrong, it does not mean the same as Doldrums.
• frustration: annoyance at being blocked - wrong, it does not mean the same as Doldrums.
• ebullience: bubbling enthusiasm - wrong, it does not mean the same as Doldrums.