Answer
5 bits
Step-by-step explanation
A bit is the least or the smallest unit of data in a computer. They are the units of information in information theory, consisting of the amount of information required to specify one of two alternatives 0 and 1. This is because A bit has a single binary value, either 0 or 1
If you use roman alphabet A to Z lets use log 2(26)=4.7 bits. when you round off it will be 5 bits.