(a) Liens and security interests in favor of the Bank;
(b) Liens for taxes not yet due and payable or otherwise being contested in good faith and for which appropriate reserves are maintained ;
(c) Other liens imposed by law not yet due and payable, or otherwise being contested in good faith and for which appropriate reserves are maintained;
(d) purchase money security interests on any property hereafter acquired, provided that such lien shall attach only to the property acquired.