Answer:

A

B

O

We have spotted ABO (3 Letters) a total of 22 times in our database. Below you may see the clues associated with ABO and also when and where was it last seen:

Referring crossword puzzle clues

• Blood-typing system
• Blood type letters
• Transfusion letters
• Blood-typing letters

Usage among publishers:

• Newsday: Apr 19, 2024
• Newsday: Jul 23, 2023
• Wall Street Journal: Feb 23, 2023
• LA Times: Feb 11, 2023
• Wall Street Journal: Jan 21, 2023