[单选题]
1. Why are fatty acids or phospholipids important in the+xa (bldyksxt,*42wm formation of cra29fm+e . ugaells and their compugafea+.r 2m9 onents?
A. They are soluble.
B. They allow compartmentalisation of cells and organelles.
C. They only allow compartmentalisation of the nucleus.
D. They form cell walls.