Step 1: Understanding the Concept
Nitrogenous bases are purines (adenine, guanine) or pyrimidines.
Step 2: Count
Pyrimidines in nucleic acids are cytosine, thymine and uracil.
Step 3: Conclusion
There are 3 pyrimidine bases.
Final Answer:
There are three pyrimidine bases.
\[ \boxed{\text{(C) }3} \]