Final answer:
The number of campaigns that successful candidates run is not explicitly mentioned by the author. Instead, the provided texts detail the process and challenges of modern presidential campaigns. Thus, the correct option is 4.
Step-by-step explanation:
The author does not specify the exact number of campaigns successful candidates run, therefore the answer should be that the number of campaigns they run is not mentioned.
What the text does convey is the intense nature of modern presidential campaigns, which involve steps such as fundraising, strategizing, garnering name recognition, and appealing to both primary and general election voters.
For presidential candidates, the process also includes participating in primaries and caucuses, and for some, running multistate campaigns. However, the text emphasizes the challenges and demands of the campaign process rather than providing a specific number of campaigns successful candidates undertake. Thus, the correct option is 4.