I guess the answer given in the mock is correct. Overriding in javax.* means a webapp will be able to override all the classes in the javax package. Does your webapp or as a matter of fact, any webapp overrides classes in javax.crypto?? or javax.imageio?? or javax.management?? or javax.naming. I guess the answer given by the mock exam is correct.
SCJP 1.4, SCWCD 1.4 - Hints for you, Certified Scrum Master
Did a rm -R / to find out that I lost my entire Linux installation!