What causes air to enter into a tornado? A. The air pressure is lower outside the tornado than inside
B. The air pressure is higher inside the tornado than outside
C. The air pressure is lower inside the tornado than outside
D. The air pressure is the same inside and outside the tornado

The air pressure is lower inside the tornado than outside

Explanation:

Tornadoes form in unusually violent thunderstorms when there is sufficient (1) instability and (2) wind shear present in the lower atmosphere. ... For instance, dry air in the middle atmosphere can be rapidly cooled by rain in the thunderstorm, strengthening the downdrafts that asist in tornado formation

c is the correct answer!