Which correctly links the independent clauses in this compound sentence from section 7? a) his travels were sometimes in lands never before visited by europeans; he had many unique adventures with the almost unknown tribes of asia. b) his travels were sometimes in lands never before visited by europeans; so he had many unique adventures with the almost unknown tribes of asia. c) his travels were sometimes in lands never before visited by europeans: so he had many unique adventures, with the almost unknown tribes of asia. d) his travels were sometimes in lands never before visited by europeans, so, he had, many unique adventures with the almost unknown tribes of asia.