According to the Harvard Research Project, the three primary and interrelated factors critical to achieving youth outcomes are   

A. beginning on time, daily interaction, and strict discipline. B. enjoyable transitions, friendly parent-teacher relations, and imaginative stories. C. planning, relevance, and structure. D. access to and sustained participation, high-quality curriculum, and strong partnerships. 

D.

D. access to and sustained participation, high-quality curriculum, and strong partnerships.

To find the answer to this question, you can start by conducting a search using the keywords "Harvard Research Project" and "youth outcomes." This will help you find relevant sources and information about the research project.

Once you have identified a reliable source, such as a journal article, report, or official website, you can look for specific information about the factors critical to achieving youth outcomes. This may involve reading through the document or using the search function to find key terms.

In this case, the answer is option D: access to and sustained participation, high-quality curriculum, and strong partnerships. These three factors are identified by the Harvard Research Project as being critical to achieving positive outcomes for young people.

It is important to note that the answer may vary depending on the specific study or research project being referenced. Therefore, it is always a good idea to consult the original source to ensure accuracy and validity.