The word that has a positive meaning is (C.) adventure.
The word "adventure" has a positive connotation since it is defined as an unusual and remarkable experience that produces excitement. It is a word that suggests a good feeling and a pleasing emotional connection. On the other hand, "day" and "street" are words that have a neutral meaning, while "prisoner", which refers to a person deprived of liberty and kept under confinement, is associated with a bad feeling and; therefore, it has a negative connotation.