In the code segment below, what $<$ expression$>$ can be used to check if the entered

string is in a valid form for a phone number in the form of $($###$)$

###$$####$$

valid $=($len$($string$)==14)$

while valid and expression$>$:

if position $==0$:

valid $=$ string$[$position$]=="("$

elif position $=4$:

valid $=$ string$[$position$]==")"$

elif position $==9$:

valid $=$ string$[$position$]=="-"$

valid $=$ string $[$position$]$ isdigit$()$

position $=$ position $+1$

print$("$The string contains a valid phone number."$)$

print$("$The string does not contain a valid phone number."$)$

Author: MK$,$ Editor$($s$)$: JFM

a$.$ position $<=$ len$($string$)$

cross out

b$.$ position $<$ len$($string$)$

cross out

c$.$ string $=$ valid

Cross oul

d$.$ position $==$ valid

e$.$ len$($string$)==$ len$($valid$)$