which costs the most per capsule?

(A.) 50 capsules for $9.50
(B.) 100 capsules for $16.32
(C.) 500 capsules for $45.00

A.a
B.b
C.c
D. They all cost the same amount per capsule

A. 50 capsules for $9.50 costs the most per capsule.

Calculation:
(A) Cost per capsule = $9.50 / 50 = $0.19 per capsule
(B) Cost per capsule = $16.32 / 100 = $0.1632 per capsule
(C) Cost per capsule = $45.00 / 500 = $0.09 per capsule

Therefore, option A costs the most per capsule at $0.19.