Pick a Sentence, Any Sentence

So I've bitten the bullet and I'm starting to contact agents. It is going to be a long and arduous process, and who knows where it will lead, but I know I'll learn a lot. I've already discovered one thing:

Agents ask really tough questions.

I understand they have to weed through dozens and dozens of query letters and proposals. So it only makes sense that they ask about your goals, your social media platform, your experience. But here's one I came across today -

“What is your favourite sentence in the manuscript you are submitting?”

Really? REALLY?

It's tough enough choosing a two hundred word excerpt. But a sentence?

Do I go straight for the hot and sexy – show them I'm not afraid to make my readers blush?

Do I search for something poetic and descriptive?

What about a line of dialogue – which I consider one of my strengths as a writer?

NO LIFE BUT THIS is an 80,000 word manuscript (my longest ever). How do I find that perfect gem of a sentence that shows my talent (such as it is) as well as conflict, romance and character?

How??

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