Which of the following statements is true about MPLS: a. MPLS can be used to transport voice and data, and its traffic should be protected with encryption. b. MPLS can be used to transport voice and...

Which of the following statements is true about MPLS:

a. MPLS can be used to transport voice and data, and its traffic should be protected with encryption.

b. MPLS can be used to transport voice and data, and its traffic does not need to be protected with encryption.

c. MPLS is used for data only, and its traffic should be protected with encryption.

d. MPLS is used for voice only, and its traffic should be protected with encryption.