Answer
The loops and the N- and C-terminal pieces of the protein are in aqueous spaces, so they should be composed of amino acids with R groups which can interact with water, such as postively- and negatively-charged R groups. In contrast the portions which span the membrane 4 times should have hydrophobic R groups so that those can interact with the interior of membrane.
Work Step by Step
To get to this answer, think about the chemical nature (hydrophillic, hydrophobic) of each place where some of the protein is found, and then think about the chemistry of R groups and how that should match those places.
