Find the Cardinal Number of the Set $\{ x \mid x$

Find the cardinal number of the set.
- $\{ x \mid x$ is a decimal between 63 and $64 \}$

A) 2
B) 2

C) 11ecd4d9_c000_9d1a_bc77_39072787d115_TB5007_11

D) $\mathrm { c }$