Which voice translation rule will expand extensions that are in the 3000-3999 range to a 10-digit number?

Which voice translation rule will expand extensions that are in the 3000-3999 range to a 10-digit number?
A. /^…\(… .$\)/^1/
B. /3…//4085553/
C. /^3…\(… .$\)//408555\1/
D. /^3…\(… .$\)//408555\
E. /^3…$//408555&/