<span>Coordinate is the correct answer. Coordinate adjectives modify the same noun - for example, the noun 'dress' in the flowery, pink dress is modified by the co ordinating adjectives 'flowery' and 'pink'. In this case, they are separated by a comma. To work out whether adjectives are co ordinating, try placing and between them.</span>
When she brought up dating he was extremely reticent about his personal life, meaning he was more shy, closed off, E. fits this because he wouldn't reveal what he actually wanted to say.