Vall Street Inc declares bankruptcy and the debtors are getting in line. The Company has (a) $1M of 1st lien term loan, and (b) $2M of 2nd lien term loan. It also appears that the Company has (c) unpaid tax obligations of $500K and (d) $4M of preferred equity outstanding. Rank the claimants in order of priority. a, b, c, d d, a, b, c a,b,d,c c,a,b,d