Hello, so this is a public version of the test that our professor gave out:

You are trying to bio-engineer a virus to carry particular genes between human cells. The virus must not only be able to move between cells and copy-and-carry particular genes, but it also should have as small of a genome as possible so that it can make many copies of itself. Which of the following aspects of viruses will be important for this bioengineered vector?

Can you possibly come up with 2~3 option for this answer? And i would have to explain why too.