Name the first Sahabi who murdered disbeliever in the way of Allah?

Posted by

(a) Hazrat Saad bin Abi Waqqas (RA)
(b) Hazrat Umar (RA)
(c) Hazrat Hamza (RA)
(d) Hazrat Ali (RA)

See also  How much is the rate of Ushr on the produce of artificially irrigated land?