Final answer:
The preassessment phase where a PHN drives through a town to observe health problems is known as a windshield survey.
Step-by-step explanation:
The activity described where a Public Health Nurse (PHN) was observing health problems in a town through visual inspection by driving through, and noting the presence of for-sale signs, lack of green space, and trash in the streets, is known as a windshield survey. This is a method used in community health to collect data by literally observing a community from the window of a vehicle, making it a rapid and informal assessment of community needs and resources. The other options given, such as Community themes and strengths assessment, Community Health Assessment aNd Group Evaluation (CHANGE), and community health status assessment, do not typically involve this observational approach while moving through the community.