The K⁺ channel is an example of a transmembrane protein (a protein that spans the phospholipid bilayer of the plasma membrane). What types of amino acids are likely to be found?

(a) Lining the channel through which K passes,

(b) In contact with the hydrophobic core of the phospholipids bilayer containing fatty acyl groups, 

(c) In the cytosolic domain of the protein, and

(d) In the extracellular domain of the protein?