For proving execution of a registered will
a) Be necessary to call at least two attesting witness
b) Be necessary to call at least one attesting witness
c) Not necessary to call any attesting witness
d) Be necessary to call registrar
a) Be necessary to call at least two attesting witness
b) Be necessary to call at least one attesting witness
c) Not necessary to call any attesting witness
d) Be necessary to call registrar