To find the L.C.M., we first find the prime factorization of each number:
\[
33 = 3 \times 11, \quad 54 = 2 \times 3^3, \quad 108 = 2^2 \times 3^3, \quad 165 = 3 \times 5 \times 11, \quad 198 = 2 \times 3^2 \times 11.
\]
Now, the L.C.M. is found by taking the highest powers of each prime factor:
\[
\text{L.C.M.} = 2^2 \times 3^3 \times 5 \times 11 = 5940.
\]
Thus, the L.C.M. of 33, 54, 108, 165, and 198 is 5940, which corresponds to option (3).