Consider the following valid shell script:

#1 /bin/bash
sum= 0
TMP1-./TMP1
echo -e "81n7\n6" $TMP1

while read num
do

echo "TRACE: In Loop"
echo "TRACE: num: $num"
sum- expr $sum $num
echo "TRACE: sum: $sum"
echo -e "TRACE: End of Loop\n"
done < $TMP1

Which one of the following statements is correct: Group of answer choices

a. The contents of the file TMP1 will be read into the while loop.
b. This script will exit with an error, because no file named TMP1 will exist when the while loop runs.
c. The variable sum will contain the value 23 at the end of the script, just before it exits and is unloaded from memory.
d. The first line has no effect: whatever shell you run this script from will be the shell of execution, not the one indicated in the first line.
e. The backtick characters in the line with sum and expr can be replaced with double quote characters, like so; sum-"expr $sum+ Snum", and the numerical summation intended will still occur.