How many chips are needed to build the BCD adder?

a$.2-$ two $7483$ adders

b$.3-$ one $7483$ adder, one $7408$ AND, and one $7432$ OR

c$.4-$ two $7483$ adders, one $7408$ AND, and one $7432$ OR

d$.5-$two $7483$ adders, one $7404$ inverter, one $7408$ AND, and one $7432$ OR