The Spanish conquistadors held Tenochtitlan under siege for approximately 93 days in 1521. Therefore, the correct option is C.
To find the answer to your question, we need to analyze historical records. The siege of Tenochtitlan by the Spanish conquistadors in 1521 was a significant event in the Spanish conquest of the Aztec Empire. The duration of the siege can vary depending on the sources consulted. However, the most commonly accepted answer is 75 days, which means the correct option is (b) 75 days.
