I’m afraid my youngest son has never been particularly quick on the _______?

Uptake

Upkeep

Uptorn

None of these

I’m afraid my youngest son has never been particularly quick on the uptake.

مجھے ڈر ہے کہ میرا سب سے چھوٹا بیٹا کبھی بھی خاص طور پر تیز نہیں ہوا۔

Uptake means شامل ہونے کا عمل

"Quick on the uptake" means quick to understand things.