Four identical light bulbs are placed in two different circuits with identical batteries. Bulbs A and B

Question:

Four identical light bulbs are placed in two different circuits with identical batteries. Bulbs A and B are connected in series with the battery. Bulbs C and D are connected in parallel across the battery.
(a) Rank the brightness of the bulbs.
(b) What happens to the brightness of bulb B if bulb A is replaced by a wire?
(c) What happens to the brightness of bulb C if bulb D is removed from the circuit?