In this example question it asks, which of the following statements about lipids are not true?

Option A: Steroids are a class of lipids which cannot be hydrolyzed by water. Remember when we looked at that graph where we had the two broad groups where lipids are either hydrolyzable or not hydrolyzable, we saw that steroids were indeed in the not hydrolyzable category. So, this statement here is true.

Option B: All lipids are insoluble in non-polar solvents but soluble in polar solvents. Lipids themselves, we said that they are hydrophobic because they are non-polar. Because they're non-polar, they would be soluble in non-polar solvents such as hexanes, but they would be insoluble in solvents like water. Thus, this statement is false, and it is our answer.

Option C: Certain lipids play an important role as components of biological membranes. Yes, when we're talking about our phospholipids, we know that from biology we have a connection between phospholipids and biological membranes, so this is true.

Option D: Lipids contain a large number of non-polar Carbon Hydrogen bonds making them overall non-polar. This is true. Although they possess a polar carboxylic acid end when it comes to fatty acids for those types of lipids, not all lipids have that. Lipids, basically overall, are non-polar because of the large presence of Carbon Hydrogen bonds. So, this statement here is true.

So, out of all our choices, only option B is an incorrect statement and therefore our final answer.