Plz help 13) Choose the correct answer.

Which situation represents a proportional relationship?

a) the total cost of purchasing unlimited pizza slices for $9.99 at a buffet-style restaurant

B) the total cost of purchasing dress hats for $24.95 each and a hat box for $9.99

C) the total cost of purchasing coordinated T-shirts and shorts for $19.50 per outfit

D) the total cost of buying DVDs for $15.95 each plus a shipping fee of $6.75

Aking and his army will attempt to capture a fortress. the left and right flanks break off from the main group to attack the west and east guard towers. suppose the left flank has a 60% chance of success and the right flank has a 75% chance of success, independently of one another. if both flanks capture their respective targets, then the king has a 98% chance of successfully taking the fort. if, however, only the left flank captures its tower, the king has an 80% chance of success; if only the right flank succeeds, the king has a 50% chance. if both flanks fail, then the king's chance of capturing the fort drops to 20%. it turns out the king captures the fort. what is the probability that one, and only one, flank was successful (either the left, or the right, but not both)? (round your answer to 3 decimal places)