What is a key design aspect to be considered when designing an IP network that will be carrying real-time VoIP traffic? 

Answer options:

A. Minimizing total bidirectional end-to-end delay to 0-150 ms
B. Minimizing total unidirectional end-to-end delay to 150-500 ms
C. Minimizing total bidirectional end-to-end delay to 0-50 ms
D. Minimizing total unidirectional end-to-end delay to 0-150 ms

D