For a series circuit: а. the value of resistance may be different for each resistor in the circuit.
b. the total resistance is the sum of the resistance in the circuit.
c. the total resistance increases as resistors are added to the circuit.
d. All of the above

it may be wrong but i think its a

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.