When Cortés and his soldiers first arrived in the Aztec capital of Tenochtitlán,
 a
they immediately killed the Aztec leader Moctezuma and took control of the city.
 b
the Spanish army became ill with smallpox.
 c
Cortés and his men decided to return to Spain because they feared the large Aztec army.
 d
Moctezuma welcomed them as honored guests.