The four digit code is 5934 (no space).
Letter A = 3 + 2 = 5
Letter B = A + 4 = 5 +4 = 9
Letter C = 4 - 1 = 3
Letter D = 3 + 1 = 4
Virus is defined as the microorganism that is made up of either DNA or RNA and it is surrounded by a protein coat.
While bacteria is defined as a single celled microorganism that lacks membrane bound organelles.
From the question, the answer to the alphabet A to B is 5, 9, 3 and 4.
Therefore, the four digit code is 5934 (no space)
Learn more about bacteria here:
https://brainly.com/question/6941760
