Answer:
1) C. import
Glen is a US citizen buying imported goods (video game). Japan is a foreign country that produced the video game. The market where the product is bought is the US (domestic market). So, when the domestic consumer buys a foreign consumer good in the domestic market, it is an example of import.
2) B. neither
In the US, buying a good in a US state that is produced in a different state is not considered an import. In the US, import is defined at federal level. Therefore, this is not an example of import, nor export. Import would only be considered if the good originated from a non-US country.
3) B. neither
This event is completely based in the country that is not the domestic country, so this is not an example of import, nor export. Although the domestic country in our perspective is not Japan, here a product is bought in the same country where it is produced.
4) A. export
This is a typical export example, where the US (via the state of Iowa) exports its goods (corn) to a business in China. From the perspective of our domestic country (the US), corn is exported to a foreign country, and consumed there afterward. NOTE - it wouldn't be considered as export to transfer good from one US state to another
5) A. export
This is also an example of export, where a natural resource produced (drilled) in the US is sold to a foreign country (Brazil and Mexico). The definition of export is all about this - producing a good in our domestic country and selling it to a foreign one.