As the scuba diver descended lower into the depths of the reef, he came across a sunken ship. He could not approach it because there was a very large shark swimming about. Which revision best combines these sentences into a compound-complex sentence?
a) As the scuba diver descended lower into the depths of the reef, he came across a sunken ship, but he could not approach it because there was a very large shark swimming about.
b) As the scuba diver descended lower into the depths of the reef, he came across a sunken ship, but he could not approach it because there was a very large shark swimming about.
c) As the scuba diver descended lower into the depths of the reef, he came across a sunken ship. He could not approach it since there was a very large shark swimming about.
d) The scuba diver descended lower into the depths of the reef and came across a sunken ship; however, he could not approach it; there was a very large shark swimming about.
