Who stated that there is an exchange of materials when two objects come into contact with each other?
a.) leone lattes
b.) mathieu orfila
c.) his duan yu
d.) edmond locard

The correct answer to this question is D. Edmond Locard.                                                                                                 
This can be explained by the Locard's Exchange Principle which states that when two objects come in contact with each other, a cross-transfer of materials occurs. Edmond Locard also said that every criminal can be linked to a crime by dust atoms taken from the crime scene.

The answer is option a