Loni delivers her Mazda to be repaired at Nile's Body Shop. Loni agrees to pay cash. Nile performs, but Loni does not pay. Nile tells Loni that he wil keep the car until she pays. This is
a. a judicial lien.
b. a mechanic's lien.
c. an artisan's lien.
d. a violation of most states' laws