What word best describes Professor Irwin’s attitude toward the student

A．A person should probably be the least afraid of a dwarf shark.
B．A person should probably be the least afraid of a tiger shark.
C．A person should probably be the least afraid of a bull shark.
D．A person should probably be the least afraid of a great white shark.

A．Beginners have difficulty distinguishing the pronunciation of words.
B．Advanced students remember words by their meaning.
C．It is difficult to remember words that have the same meaning.
D．It is difficult to remember words that sound alike.