Take somebody up on something
"'Honestly, love,' said Mavis, unable to hide her doubt, 'you're welcome to use my car any time.'
'Thanks for the offer. I might take you up on it some time, but it's a beautiful afternoon for a ride.'" ("Watercolours")
to take somebody up on something - to accept an offer that someone has made
Could I take you up on that offer of a lift, Rob? (CALD)
"The world was a fantastic, marvelous, awesome place, Rose decided."