Which equation has no real solution: e^x=2, e^e^x=2, or e^e^e^x=2?

Which equation has no real solutions? (A) e^x=2 (B) e^e^x=2 (C) e^e^e^x=2 (D) None of these I came up with this question and posted it on my Instagram. Many people thought the answer was D.   / c8wcoyioh0o   ---------------------------------------- Big thanks to my Patrons for the full-marathon support! Ben D, Grant S, Mark M, Phillippe S. Michael Z, Camille E. Nolan C. Jan P. Devun C. Stefan C. Budoray Ethan BW 💪 Support this channel and get my math notes by becoming a patron:   / blackpenredpen   🛍 Shop my math t-shirt & hoodies: https://amzn.to/3qBeuw6 ---------------------------------------- #blackpenredpen #math