After being defeated in 2007, the Australian Liberal party needed to find a leader who could return them to power; they hope that the current leader, a _______ social conservative who leads the opposition on a number of issues, including stem cell research and carbon trading, and who wrote a book with the telling title Battlelines, may be the man for the job.

a. Compliant

b. Circumspect

c. Diffident

d. Pugnacious

e. Milquetoast

f. Disputatious