In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Q: Question: Which of the following compounds in a fundamental intermediate of the synthesis of triacylglycerols and phospholipids: 
 Options:  <1> CDP-choline. <2> Phosphatidate <3> Triglyceride <4> Phosphatidylserine <5> CDP-diacylglycerol.
A:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
2