Which of the following transmembrane ion channels is/are most closely associated with hyper polarization and IPSP? (Select all that apply.)

a. voltage gated K+ channels
b. ligand gated Ca+2 channels
c. ligand gated Na+/K+ channels
d. voltage gated Na+ channels
e. ligand gated Cl- channels
f. voltage gated Ca+2 channels

a. voltage gated K+ channels

e. ligand gated Cl- channels