Which one is NOT correct about number representation in computers? $($a$)$ Integers are represented as exact numbers and increasing the number of bytes in an integer could increase the value that is represented. $($b$)$ The ASCII code uses one byte to represent different characters and symbols. $($c$)$ If a number is smaller than the machine epsilon, an error will occur. $($d$)$ Computers can store rational numbers as single$-$ or double$-$precision values.