Taking the carbonyl group as C-1 at the top, the sugar shown is best described as

There is a CHO group and five carbons, so it is an aldopentose. The highest-numbered stereocentre (C-4) is S, whereas D-sugars have R there (as D-glyceraldehyde is R), which places the OH on the left in the Fischer projection. The sugar is L-arabinose, an L-aldopentose.