Which sentence indicates the author acknowledges an opposing viewpoint?

a. without skateparks, skaters are forced to use public areas like parking lots or streets, which can damage property and lead to conflicts with pedestrians or drivers.
b. they also give skaters a place to hang out, socialize, and be active in a positive way.
c. building quality skateparks shows that a community values its youth and supports healthy activities.
d. some people worry that skateparks promote rebellious behavior, but the reality is they help kids develop skills, confidence, and a sense of belonging.