Multiple choice general knowledge Inventor of Ball pen Wilnelm Conrad Roentgen Einstein ladislas biro John Stepherd Barron Reveal answer Fill a bubble to check yourself C Correct answer Explanation László Bíró (spelled 'ladislas biro' in the option) invented the modern ballpoint pen in the 1930s. His design used a tiny ball bearing to distribute ink smoothly, solving the problem of ink smudging that plagued earlier fountain pens.