There is a possible bug or oversight on the One-Liners exercise.
I kept banging my head against the wall trying to sort out why this was not working...
puts "One is less than two!" if 1 < 2
I kept getting error to check 'if statement' was correct, but the answer would resolve in the terminal as expected. I noticed in the error message after reading it seemingly hundreds of times that they were using single quotes around the string instead of double quotes like has been used on every other example so far.
So switching my response to single quotes around the string...
puts 'One is less than two!' if 1 < 2
I finally got the green light to move on.