$3\times2\times1=6$  $4\times3\times2=24$  $24\times6=144$ 
How many ways are there to rearrange the letters in the word \textquotesingle BEAUTY\textquotesingle{} if the vowels are never together? 

a. $$24$$ 
b. $$48$$ 
c. $$144$$ 
d. $$480$$ 
e. $$720$$ 