Word2003/XP

A user has a document and is attempting to insert num fields. The "(a)" is
the way they want the number ..but they want the "(b)" on the next paragraph
as the example below. When I put in Ctrl+Alt+L instead of getting a "(b)" I
get a "Section 3".

What are we (me) doing wrong?

Thank you.

EXAMPLE

Text text texttexttexttexttexttext texttexttext text text text texttext
texttext texttext (a) texttext texttext texttext texttext texttext texttext
texttext texttext text.

(b) More testing testing test testing testing test testing testing test
testing testing test testing testing test testing testing test testing
testing test testing testing test testing testing test testing testing test
testing testing test testing testing test testing testing test.