Answer: B, √60 .
Step-by-step explanation: Irrational numbers are numbers that can not be written in the form of a/b. To further explain, this includes any decimals that go on forever and are non-repeating, such as pi 3.14159... Numbers that have repeating numbers like 5.5555555 are rational, so don't get confused between the two! The square root of 60 is 7.74596669 making it the only irrational number here.