To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) %partNo%=="WEBM*" - This option is incorrect because the asterisk (*) is not a valid wildcard character in this context. It should be replaced with a regular expression.
Option B) %partNo%==/^WEBM/ - This option is correct. The syntax "/^WEBM/" is a regular expression that matches any string that begins with "WEBM". Therefore, it satisfies the requirement of the question.
Option C) %partNo%==/$WEBM/ - This option is incorrect because the dollar sign ($) is not a valid character in this context. It should be replaced with a regular expression.
Option D) %partNo%!=/WEBM./ - This option is incorrect because the question asks for the label of the service, not the condition to exclude the service. Additionally, the regular expression "/WEBM./" matches any string that contains "WEBM" followed by any number of characters.
The correct answer is B. This option is correct because "/^WEBM/" is a regular expression that matches any string that begins with "WEBM".