Which of the following increases rennin release?: (A) Parasympathetic stimulation, (B) Renal hypertension, (C) Renal hyperperfusion, (D) Decreased Nacl in macula densa
Answer is D. Factor which increase rennin release :

Renal hypoperfusion and hypotension
Symphathetic stimulation
Renal ischaemia
Decreased Nacl in macula densa