hey im doing analogies... and i need help on some of them

Question

Seatbelts : Cars::
a)filters:coffee machines
b)oven:stove
c)radio:sound waves
d)color:paper
e)bricks:contruction

and i thought A would fit into the seatbelts and cars but whats a sentence that i can use to show that they are similar?

Filters are necessary for coffee machines because they protect the finished coffee from the grounds. How are seatbelts necessary for cars?

seatbelts protects the person in the car?

Right. :-)