With a local guide _____ the way ,they had no trouble ___ ou

With a local guide _____ the way ,they had no trouble ___ out of the forest.
With a local guide _____ the way ,they had no trouble ___ out of the forest.
A.leading;walking B.led:walked C.lead:walking D.leads;walking
我选的是A,请说明理由.第一个空可以填 to lead 请详细说明理由