Answer:
These investigations most likely tell him that A. Heat makes water evaporate faster.
Step-by-step explanation:
The heat from the sun makes the water molecules move faster and faster, until they move so fast they escape as a gas.
B answer is not legit because water does evaporate in the grass.
C answer is not legit because sidewalks without heat from the sun doesn't make water evaporate
D answer is not legit because water does evaporate in shade; evaporation is slower but still occurring