Final answer:
The primary mission of submarine forces is to destroy supply ships in the field of naval operations or submarine missions.
Step-by-step explanation:
The primary mission of submarine forces is to destroy supply ships in the field of naval operations or submarine missions. In World War I, German submarines called U-boats were highly effective at sinking merchant ships, disrupting the flow of supplies to the Allies. Similarly, in World War II, the convoy system, which involved grouping many ships together escorted by destroyers, helped protect against submarine attacks. The use of submarines to target supply ships remains a key strategy in naval warfare.