Question 301356
The third leg can vary from between A-B to A+B but not including those two values. 
In this case, A=15, B=4, the final leg can range from 11 to 19.  
A. {{{ 13 }}} (YES)

B. {{{15}}} (YES)
C. {{{19 }}}(NO)
D. {{{4 }}}(NO)
E. {{{11}}} (NO)
F. {{{12 }}}(YES)