If the pth, qth and rth terms of an H.P be a, b, c respectively, then \(\left|\begin{array}{ccc} \rm bc & \rm ca & \rm ab \\ \rm p & \rm q & \rm r \\ 1 & 1 & 1\end{array}\right|\) is equal to
1
abc
2
pqr
3
0
4
More than one of the above
5
None of the above