Which of the following would cause the oxygen dissociation curve to shift to the left?

A shift to the left in the oxygen dissociation curve indicates an increased affinity of hemoglobin for oxygen. This means hemoglobin is more likely to bind to oxygen and less willing to release it to the tissues. Various physiological factors influence this curve, and among the choices, lower temperature is known to cause such a shift.

When the temperature decreases, the kinetic energy of the molecules involved in hemoglobin's interaction with oxygen decreases. This results in hemoglobin holding onto oxygen more tightly, which reflects an increased affinity for oxygen. In conditions of lower body temperature, such as during hypothermia, the hemoglobin's release of oxygen to tissues is diminished, effectively shifting the curve to the left.

In contrast, factors like exercise tend to raise body temperature and also produce a buildup of carbon dioxide and lactic acid, leading to a right shift, which decreases hemoglobin's affinity for oxygen. Lung disease and congestive heart failure similarly create conditions favoring a right shift due to decreased oxygen availability and altered blood flow dynamics, respectively.

Therefore, lower temperature is indeed the correct answer as it directly correlates with increased oxygen affinity and a leftward shift in the oxygen dissociation curve.