Choose the alternative which suggests a coherent paragraph.
A. These researchers have become so knowledgeable about their subjects that they have been guiding us to the right place at the right time.
B. The great increase during the past decade in the number of scientists actively involved in observing animals in the wild is very important.
C. They have guided us to see exactly that aspect of behaviour that was of particular interest to us.
D. Almost every group of large animals is now being studied by scientists. everywhere.