Hi Haley! For a, we will consider octane as the parent chain. We are actually looking at the carbon 3 and 4 for the Newman projection. We will start counting from the substituent at the top passing through the 2 carbons in the circle then to the substituents from the top right side. Here’s the name and structure of it:
For b, we will consider pentane as the parent chain. We also have an aldehyde which has a higher priority than alcohols so we have to name it as pentaldehyde. Now we have to figure the R/S configuration of carbons 2, 3 and 4. I will not go to the full details on how to get the absolute configuration, you just have to keep in mind the priorities to determine if it is R or S. The correct name for this is: (2S,3R,4S)-2,3,4,5-tetrahydroxypentanal
You can review R/S naming here: https://www.clutchprep.com/organic-chemistry/the-r-and-s-naming-system/?c_id=10231
Hope that helps!