The compositions in atom% of an alloy that consists of 97% wt% Al & 3 wt% Cu are:
a. 99.7 at% A1 & 0.3 at% Cu.
b. 95.7 at% Al & 4.3 at% Cu.
c. 89.7 at% A1 & 10.3 at% Cu.
d. 98.7 at% Al & 1.3 at% Cu.
e. 97.8 at% Al & 2.2 at% Cu.