The properties of fatty acids are determined by:

• A. The length of the hydrocarbon chain.
• B. The degree of saturation (how many double bonds there are between carbons).
• C. The position & configuration of double bonds between carbons.
• D. All of the above.

Answer: (D)

Verified step by step guidance

1. Understand the structure of fatty acids: Fatty acids are composed of a hydrocarbon chain and a carboxyl group (-COOH). The properties of fatty acids are influenced by the characteristics of their hydrocarbon chains.
2. Examine the length of the hydrocarbon chain: Longer chains tend to have higher melting points and are less soluble in water, while shorter chains are more soluble and have lower melting points.
3. Analyze the degree of saturation: Saturation refers to the presence of single bonds between carbon atoms. Unsaturated fatty acids contain one or more double bonds, which introduce kinks in the chain, affecting fluidity and melting point.
4. Consider the position and configuration of double bonds: The location of double bonds (e.g., omega-3 or omega-6) and their configuration (cis or trans) influence the fatty acid's physical and biological properties.
5. Conclude that all these factors—chain length, degree of saturation, and double bond position/configuration—collectively determine the properties of fatty acids, making 'All of the above' the correct answer.