Alex is willing to buy the last ticket to the Billy Bragg concert for $15, while Jake is willing to pay $25. Alex is first in line and buys a ticket for $15. He then resells his ticket to Jake for $20. By reselling the ticket instead of going to the concert himself, Alex caused:
a) a deadweight loss of $5.
b) total surplus to increase.
c) total surplus to decrease.
d) consumer surplus to decrease and producer surplus to increase.