Final answer:
Option b) Select only agricultural lands within 50m of highways is the selection based on both attribute and location.
Step-by-step explanation:
The example of selection based on both attribute and location is b) Select only agricultural lands within 50m of highways. This choice includes a specific attribute, agricultural land, and a location criterion, being within 50 meters of highways.
The other options listed do not combine both an attribute and a location-based condition as directly as option b does. For instance, option a) is solely location-based, c) is attribute-based as it only specifies a population size, and d) specifies a location but no attribute of the schools.
An example of selection based on both attribute and location is a) Select all land parcels within 50m of highways. This selection criteria considers the attribute of proximity to highways as well as the location of the land parcels.
By selecting land parcels within 50m of highways, one is considering both the specific attribute of being close to highways and the location of the land parcels in relation to the highways.
This selection could be relevant, for example, in urban planning or real estate development to identify areas with good accessibility to highways.