Questions

Dr. Gullapalli N. Rao, the founder and chair of the LV Prasad Eye Institute (Hyderabad), has been selected to the 2017 Ophthalmology Hall of Fame instituted by the American Society of Cataract and Refractive Surgery (ASCRS). He will be honoured at the induction ceremony in Los Angeles on May 6, 2017 at the annual meeting of the ASCRS.

Currently, Rao is the President of the prestigious Academia Ophthalmologica International (AOI), a group of 80 eminent academicians in ophthalmology in the world and is a past Chair of the International Agency for the Prevention of Blindness (IAPB).

Karst is a type of landscape that is characterized by caverns, caves, sinkholes, and underground streams. These features were all caused by erosion of the underlying rock.

Limestone type of rock usually underlies a karst landscape.

In the given options, "His stomach rumbled like an approaching train" is an example of Simile.

All the other options are examples of metaphors. 

Simile and Metaphor are both figure of speeches in English which are used for comparing things but the only difference is Simile uses LIKE or AS words in comparing and metaphor directly compares without using any words.