Fat is less soluble in water than a phospholipid because fats are completely hydrophobic without a hydrophilic head, unlike phospholipids which have both hydrophilic heads and hydrophobic tails.
A fat molecule is less soluble in water compared to a phospholipid because it lacks any hydrophilic (water-attracting) components. Unlike fats, phospholipids are amphipathic molecules, possessing both hydrophilic heads and hydrophobic tails. The hydrophilic heads of phospholipids are attracted to water, which makes them partially soluble, while the water-fearing hydrophobic tails avoid water. Therefore, while a phospholipid has some level of interaction with water due to its hydrophilic head, a fat, being entirely hydrophobic, does not dissolve in water at all.
Is, a fat molecule is less soluble in water than a phospholipid. The correct answer to the question is: a) Fat; it lacks a hydrophilic head.