Option D Is the correct answer because “graphology” means the study of written and printed symbols and of writing systems, which means the study of handwriting.
Option A is incorrect because “forensic” means relating to courts of law, hence it is incorrect.
Option B is incorrect because “graffiti” means writing or drawings scribbled, scratched, or sprayed illicitly on a wall, hence it is different from handwriting.
Option C is incorrect because “hieroglyphics” , means enigmatic or incomprehensible symbols or writing, hence it is incorrect.