Which of the following commands creates a function in Bash that outputs the sum of two numbers?

A. function sumitup { echo $(($1 + $2)) ; }

B. command sumitup { echo $(($1 + $2)) ; }

C. function sumitup { echo $1 + $2 ; }

D. method sumitup { echo $1 + $2 ; }

E. command sumitup { echo $1 + $2 ; }