SRNF refers to:

Correct option is A

· SRNF = Slow-Release Nitrogen Fertilizers.
· Includes: sulfur-coated urea, polymer-coated urea, urea–formaldehyde, IBDU, CDU.
· Purpose: extend N availability, reduce leaching, increase NUE.
Why other options are wrong
· (b) No fertilizer called "Sulphur Rich N fertilizer".
· (c) Not a soil science term.
· (d) SRN is used sometimes, not SRNF.