Answer:
Them
Explanation:
The Indirect Object is a verbal complement. It has the function of completing the meaning of the transitive verbs which by themselves do not provide complete information. In this case the verb "to protect" does not make sense if it is alone in this sentence, then it needs a complement that will be the indirect object. To find the indirect object you need to ask the question "to protect who?" the answer will be "to protect them" then the indirect object of the sentence is "them".
