Either Sensitization or Tolerance Can Occur During Chronic Psychostimulant Administration

Either sensitization or tolerance can occur during chronic psychostimulant administration. Which statement accurately reflects these processes?

A) Sensitization occurs for purposeless behavior; tolerance occurs for positive subjective effects.
B) Sensitization occurs for positive subjective effects; tolerance occurs for purposeless behavior.
C) Both sensitization and tolerance occur for purposeless behavior, but not for positive subjective effects.
D) Both sensitization and tolerance occur for positive subjective effects, but not for purposeless behavior.