McGowan (1974) found that outcomes of advocacy were affected by

A. education of the advocate
B. Receptivity of the target
C. setting and support
D. method of implementation

To identify the correct answer, we can refer to McGowan's study from 1974. However, since I don't have access to specific research studies, I can provide an explanation of how you can approach finding the answer yourself. Here are a few steps you can take:

1. Conduct a literature search: Use academic databases such as Google Scholar, JSTOR, or PubMed to search for the study conducted by McGowan in 1974. You can use keywords like "McGowan 1974 advocacy outcomes" or "McGowan 1974 study on advocacy" to narrow down your search.

2. Filter the search results: Review the titles, abstracts, and publication dates of the search results to identify relevant articles that match the topic and timeframe you are interested in. Look for studies or articles that specifically discuss the factors affecting outcomes of advocacy.

3. Review the selected articles: Once you have identified the relevant articles, read them or their abstracts to gather information about the factors examined in McGowan's study. Pay attention to any information that mentions the relationship between outcomes of advocacy and factors like education of the advocate, receptivity of the target, setting and support, or method of implementation.

4. Determine the answer: Based on the information gathered from the selected articles, identify which factor or factors McGowan (1974) found to affect the outcomes of advocacy.

Remember, it's essential to refer to the primary sources for accurate information.