What is this announcement for vs. whom is this announcement for?

[Torsten]

Hi, I've just come across the following exercise in the New TOEIC prep book by Barron's:

What is this announcement for?
A) Schoolteachers.
B) Schoolchildren.
C) Volunteer tutors.
D) Businesspeople.

Why is the question word 'what' and not 'who' or 'whom'?

Thanks,
Torsten

TOEIC listening, talks: A radio commercial for window installations

[Jamie (K)]

Yes, the question should say "who" or "whom". This is obviously part of a long tradition of bad mistakes in English test prep books.