Answer:
Page orientation
Step-by-step explanation:
Required
What does portrait and landscape represent?
For better understanding, I'll narrow down the question to Microsoft Office Word. The explanation can be applied to other concepts.
Analysing the option one after the other.
Page layout: This is a term that describes the graphical representation of each document page, visually.
Page Size: This is a term that represents the length and width of the page. Common page sizes are LETTER, A4, A3, and so on.
The above (2) do not in any way represent what portrait and landscape represent.
Page orientation: This is a way the document is represented and it's a direct synonym for landscape and portrait.
Since (1) & (2) do not represented the given term, the last option is incorrect.
Hence,
Page orientation correctly answers the question