Ticker IBS is traded on the Pacific, Gulf and Atlantic stock Exchanges. The sequence of bids in the consolidated record is:

Time Exchange Bid

10:00:01 Atlantic 23.33
10:00:02 Pacific 23.32
10:00:03 Gulf 23.34
10:00:04 Pacific 23.40
10:00:05 Gulf 23.45
10:00:06 Pacific 23.44
10:00:07 Atlantic 23.43
10:00:08 Gulf 23.40

The NBB at 10:00:07 is:_______

a. 23.32
b. 23.43
c. 23.45
d. 23.44