1)First of all,in first if statement parenthesis are not balanced .so it is Syntax error. there is no option called "syntax error".if we forget the balancing parenthesis we can move further.
2)Someone says it return median element of a,b and c not middle element of a,b and c . But here middle and median are same.(For those who asking what is median -The median is the number that lies in the middle when all of the data numbers are written in order.) so that statement is wrong. But actually it does not return median or middle element.
3)let consider example
Trail(7,2,6) return 6
Trail(5,4,9) return 5
So from example you can conclude that it dose not return maximum or minimum or middle of element. in another case if a=b=c ,it stuck in infinite loop. so answer is d) None of the above