In comparing an oak tree with a maple tree, you can correctly say that

Answer 1

you can correctly say that they are both trees.

??

Might not be the best answer, but it IS true. :-)

Answer 2

one is deciduous, one is not.

Answer 3

actually, not true. Some oaks are deciduous.

Answer 4

Some oaks are deciduous...
Indeed they are as I have both in my garden, the evergreen is a Holm Oak.

We could say that they are both

Kingdom: Plantae ,
Angiosperms
Eudicots
Rosids