Maya is visiting her favorite candy store, the Sugar Spoon. The candy there is in self-serve bins, so Maya can pick out exactly the amount she wants. She has $30 to spend, and she wants to get a combination of saltwater taffy that costs $9 per pound and chocolate that costs $12 per pound. Which pairs (t,c) represent possible amounts of taffy and chocolate, in pounds, that Maya could buy?
◯ (2,1)
◯ (0.5,2.5)
◯ (1.5,1.25)
◯ (1,2)