Hink Pinks are one syllable rhyming word riddles. Hinky Pinky's are two-syllable rhyming word riddles. The answer to the riddle is a pair of words that rhyme with each other.
For example a Large Feline would be "Fat Cat".
An improved written communication would be "Better Letter"
Haha wow, that's embarrassing. On top of that, I just took the test myself once it got approved and I kept trying to answer that question, but it wouldn't go through... because today I can spell Bangkok correctly, but apparently yesterday (when I created the quiz whilst procrastinating at work) something else was on my mind ;)
Good catch. I'll change it.