Official Explanation
This Table Analysis problem is a classic "sort-and-scan" style problem, one for which you'll want to sort the columns to group information to your liking and then scan for relevant information.
Here you can start by employing a little bit of up-front logic:
1) If a person has a 6 in their column at any point, they were outranked by everyone in that precinct and therefore did not completely outrank anyone. (Alas, that isn't the case for any of the three candidates in question.)
2) In any row that a candidate has a 1 they've outranked everyone for that precinct.
With that in mind, if you sort for each of the three candidates in question, you'll get all of their 1s up top and can start scanning on the lower rows.
If you start with Hsieh, notice that once the column is sorted the first two rows have 1s for Hsieh, so for two full precincts Hsieh outranked everyone. From there you can use process-of-elimination on the other rows: in any row, look at the numbers better than Hsieh's and rule them out as potential candidates that Hsieh outranked.
In the third row, Hsieh has a 2 and Shah has a 1, so eliminate Shah.
In the fourth row, Hsieh has a 3 and Carter and Okafor have 1 and 2, so now you're down to Benton and Maris as potential people that Hsieh completely outranked.
In the fifth row, Hsieh has a 4 and Benton has a 3, so Benton is out (Maris with a 5 remains a possibility).
And in the sixth row, Hsieh has a 5 and Maris has a 4, so you can eliminate Maris and conclude that Hsieh didn't outrank everyone.
For Okafor you have an advantage: Maris is in the directly adjacent column, and Maris doesn't have any 1s, 2s, or 3s (meaning that Maris performed very poorly while Okafor performed quite well). This one can give you a quick scan based on that proximity: you may still want to sort by Okafor to get the 1s and 2s at the top but then notice that Maris's best is a 4 and Okafor's worst is a 4. So all of Okafor's 1s, 2s, and 3s will outrank Maris, and when you see that Okafor's 4 corresponds with Maris's 5, you can quickly conclude that Okafor did completely outrank someone: Maris.
With Shah, again sort by the relevant column for Shah. And here either of the above two strategies will work: you have quick column proximity between Shah and Maris (and you know that Maris's best is a 4 so that's an easy target). Or you can go full process of elimination. Shah's first row is a 1 so there Shah outranks everyone. From there:
The second and third rows are 2s, with Okafor and Hsieh having the 1s so eliminate those two,.
The fourth row is a 3 with Okafor and Carter as the 1 and 2, so eliminate Carter.
The fifth row is a 4, with Maris and Benton at 5 and 6 so Maris and Benton are still possibilities.
And the sixth row is a 5...but Maris has the 6 so Shah completely outranks Maris.
Therefore Shah and Okafor did completely outrank someone, but Hsieh did not.