Answer :

Answer: A) e

Step-by-step explanation:

      The only irrational number given is answer option A, the number e. Euler's number, e, is equal to about 2.718281828. It continues forever without repeating and is a real number that cannot be expressed as a fraction. As such, this is an irrational number.

      The other answer options are rational numbers. Let us review them all.

             [tex]\boxed{A}\;\;\;\;\; \displaystyle e =\frac{?}{?} \;\;\text{\sffamily X}[/tex]

             [tex]\boxed{B}\;\;\;\;\; \displaystyle 4=\frac{4}{1} \;\;\checkmark[/tex]

             [tex]\boxed{C}\;\;\;\;\; \displaystyle 10=\frac{10}{1} \;\;\checkmark[/tex]

             [tex]\boxed{D}\;\;\;\;\; \displaystyle \sqrt{100} =10=\frac{10}{1} \;\;\checkmark[/tex]