Olivia is organizing a bake sale, and their goal is to raise at least $500. So far they have raise $210. If the items are all $5 each, which inequality represents how many more items they need to sell to meet Olivia's goal?
a) 5b+210≥500
b) 5b≥500+210
c) b+500≥210
d) 5b+210≤500