Aaron needs to meet a big deadline. katy, who is not normally on his team, volunteers to out. they meet the deadline. aaron writes a heartfelt email to katy to her for her , but katy does not respond. her behavior is likely an example of

The answer to this question is the neutrality effect.
the neutrality effect refers to an occurence when someone do something that intended to receive positive response, but the receiver so that thing as a neutral emotion.. In this particular case, Katy sees Aaron's heartful email as a simple thank you without further intention, so she doesn't feel the need to reply.

The one that most represents the earths mantle would be the skin since the mantle is the upper part of the earths depths which is just like the skin of an apple.