Solving the Problem

This problem can best be solved with the "Piece-by-Piece" strategy, which involves tackling a question in parts so we're not overwhelmed with information. The first part of the problem references the "sum of the five average ratings for each of the three airlines," so let's start there:

Step 1: Calculate the Sum of the Five Average Ratings for each Airline

Airline A: $5.1 + 5.0 + 5.0 + 6.5 + 7.8 = 29.4$
Airline B: $8.0 + 5.5 + 6.4 + 6.9 + 7.5 = 34.3$
Airline C: $4.3 + 5.4 + 3.5 + 4.1 + 4.9 = 22.2$

Step 2: Determine which sum is the smallest.

Clearly, that's Airline C.
- NOTE: You don't really have to do the calculations. If you "eyeball" the chart, it's pretty obvious that Airline C has the smallest sum among the five categories.

Step 3: Find out how many airline agents (out of 100) rated Airline C first.

If we look at the pie chart, we see that $2$ travel agents ranked the airlines CBA and $20$ agents ranked the airlines CAB. That's a total of $22$ agents out of $100$.

Thus, the correct answer is $\frac{22}{100}$. Note -- if you reduce this fraction, the system counts it as wrong for some reason.