The macaroon (with sesame seeds) looking thing farthest to the left on the lightning bolt option?
For me it says "Boost your company profits for x2 multiplier for 36:00.
(I have a decoration that increases buff duration by 780 seconds, but I could have sworn the original duration of the buff was only 5 minutes.)
And FWIW, "c" is after Sp". (and switching multipliers, looks like Dc is after that) Though it feels like I hit a brick wall with ~140 levels left to 9.