###Rationale: A sterile immune ring (yellow line of demarcation)may be present where fungal antigen and host antibodies meet.Its a sign in fungal corneal ulcer Reference:Comprehensive ophthalmology,AK Khurana,6th edition,page no.106

###Answer: OPTION B IS CORRECT.
###Question: Immune ring is a feature of -
###Options:
A. Interstitial keratitis
B. Fungal corneal ulcer
C. Bacterial corneal ulcer
D. Herpes simplex keratitis
